diff options
| author | David Sommerseth <dazo@users.sourceforge.net> | 2010-07-22 22:30:27 +0200 |
|---|---|---|
| committer | David Sommerseth <dazo@users.sourceforge.net> | 2010-07-22 22:30:27 +0200 |
| commit | c70135d8ed31d133f2fb085bee01db8ad26d7fec (patch) | |
| tree | 6b1edab6b87bd4c0d5b4aeca747232e524d28b36 /openvpn.8 | |
| parent | Added win/build_exe.py script, which is similar to (diff) | |
| parent | Fixed client hang when server don't PUSH (aka the NO_SOUP_FOR_YOU patch) (diff) | |
| download | openvpn-c70135d8ed31d133f2fb085bee01db8ad26d7fec.tar.xz | |
Merge branch 'bugfix2.1' into beta2.2
Conflicts:
openvpn.8
- New option descriped (--register-dns)
Signed-off-by: David Sommerseth <dazo@users.sourceforge.net>
Diffstat (limited to 'openvpn.8')
| -rw-r--r-- | openvpn.8 | 1624 |
1 files changed, 815 insertions, 809 deletions
@@ -97,25 +97,25 @@ with a relatively lightweight footprint. .SH OPTIONS OpenVPN allows any option to be placed either on the command line or in a configuration file. Though all command line options are preceded -by a double-leading-dash ("--"), this prefix can be removed when +by a double-leading-dash ("\-\-"), this prefix can be removed when an option is placed in a configuration file. .\"********************************************************* .TP -.B --help +.B \-\-help Show options. .\"********************************************************* .TP -.B --config file +.B \-\-config file Load additional config options from .B file where each line corresponds to one command line option, -but with the leading '--' removed. +but with the leading '\-\-' removed. If -.B --config file +.B \-\-config file is the only option to the openvpn command, the -.B --config +.B \-\-config can be removed, and the command can be given as .B openvpn file @@ -187,25 +187,25 @@ secret static.key .\"********************************************************* .SS Tunnel Options: .TP -.B --mode m +.B \-\-mode m Set OpenVPN major mode. By default, OpenVPN runs in point-to-point mode ("p2p"). OpenVPN 2.0 introduces a new mode ("server") which implements a multi-client server capability. .\"********************************************************* .TP -.B --local host +.B \-\-local host Local host name or IP address for bind. If specified, OpenVPN will bind to this address only. If unspecified, OpenVPN will bind to all interfaces. .\"********************************************************* .TP -.B --remote host [port] [proto] +.B \-\-remote host [port] [proto] Remote host name or IP address. On the client, multiple -.B --remote +.B \-\-remote options may be specified for redundancy, each referring to a different OpenVPN server. Specifying multiple -.B --remote +.B \-\-remote options for this purpose is a special case of the more general connection-profile feature. See the .B <connection> @@ -214,7 +214,7 @@ documentation below. The OpenVPN client will try to connect to a server at .B host:port in the order specified by the list of -.B --remote +.B \-\-remote options. .B proto @@ -229,18 +229,18 @@ one server. Note that since UDP is connectionless, connection failure is defined by the -.B --ping +.B \-\-ping and -.B --ping-restart +.B \-\-ping-restart options. Note the following corner case: If you use multiple -.B --remote +.B \-\-remote options, AND you are dropping root privileges on the client with -.B --user +.B \-\-user and/or -.B --group, +.B \-\-group, AND the client is running a non-Windows OS, if the client needs to switch to a different server, and that server pushes back different TUN/TAP or route settings, the client may lack @@ -248,7 +248,7 @@ the necessary privileges to close and reopen the TUN/TAP interface. This could cause the client to exit with a fatal error. If -.B --remote +.B \-\-remote is unspecified, OpenVPN will listen for packets from any IP address, but will not act on those packets unless they pass all authentication tests. This requirement for authentication @@ -257,7 +257,7 @@ trusted IP addresses (it is very easy to forge a source IP address on a UDP packet). When used in TCP mode, -.B --remote +.B \-\-remote will act as a filter, rejecting connections from any host which does not match .B host. @@ -283,7 +283,7 @@ and An OpenVPN client will try each connection profile sequentially until it achieves a successful connection. -.B --remote-random +.B \-\-remote-random can be used to initially "scramble" the connection list. @@ -381,15 +381,15 @@ blocks below it. .\"********************************************************* .TP -.B --remote-random +.B \-\-remote-random When multiple -.B --remote +.B \-\-remote address/ports are specified, or if connection profiles are being used, initially randomize the order of the list as a kind of basic load-balancing measure. .\"********************************************************* .TP -.B --proto p +.B \-\-proto p Use protocol .B p for communicating with remote host. @@ -403,17 +403,17 @@ or The default protocol is .B udp when -.B --proto +.B \-\-proto is not specified. For UDP operation, -.B --proto udp +.B \-\-proto udp should be specified on both peers. For TCP operation, one peer must use -.B --proto tcp-server +.B \-\-proto tcp-server and the other must use -.B --proto tcp-client. +.B \-\-proto tcp-client. A peer started with .B tcp-server will wait indefinitely for an incoming connection. A peer @@ -421,9 +421,9 @@ started with .B tcp-client will attempt to connect, and if that fails, will sleep for 5 seconds (adjustable via the -.B --connect-retry +.B \-\-connect-retry option) and try again infinite or up to N retries (adjustable via the -.B --connect-retry-max +.B \-\-connect-retry-max option). Both TCP client and server will simulate a SIGUSR1 restart signal if either side resets the connection. @@ -443,9 +443,9 @@ application-level UDP protocols, or tunneling protocols which don't possess a built-in reliability layer. .\"********************************************************* .TP -.B --connect-retry n +.B \-\-connect-retry n For -.B --proto tcp-client, +.B \-\-proto tcp-client, take .B n as the @@ -453,16 +453,16 @@ number of seconds to wait between connection retries (default=5). .\"********************************************************* .TP -.B --connect-retry-max n +.B \-\-connect-retry-max n For -.B --proto tcp-client, +.B \-\-proto tcp-client, take .B n as the number of retries of connection attempt (default=infinite). .\"********************************************************* .TP -.B --auto-proxy +.B \-\-auto-proxy Try to sense HTTP or SOCKS proxy settings automatically. If no settings are present, a direct connection will be attempted. If both HTTP and SOCKS settings are present, HTTP will be preferred. @@ -474,7 +474,7 @@ InternetQueryOption API. This option exists in OpenVPN 2.1 or higher. .\"********************************************************* .TP -.B --http-proxy server port [authfile|'auto'|'auto-nct'] [auth-method] +.B \-\-http-proxy server port [authfile|'auto'|'auto-nct'] [auth-method] Connect to remote host through an HTTP proxy at address .B server and port @@ -509,32 +509,32 @@ determine the authentication method, but to reject weak authentication protocols such as HTTP Basic Authentication. .\"********************************************************* .TP -.B --http-proxy-retry +.B \-\-http-proxy-retry Retry indefinitely on HTTP proxy errors. If an HTTP proxy error occurs, simulate a SIGUSR1 reset. .\"********************************************************* .TP -.B --http-proxy-timeout n +.B \-\-http-proxy-timeout n Set proxy timeout to .B n seconds, default=5. .\"********************************************************* .TP -.B --http-proxy-option type [parm] +.B \-\-http-proxy-option type [parm] Set extended HTTP proxy options. Repeat to set multiple options. -.B VERSION version -- +.B VERSION version \-\- Set HTTP version number to .B version (default=1.0). -.B AGENT user-agent -- +.B AGENT user-agent \-\- Set HTTP "User-Agent" string to .B user-agent. .\"********************************************************* .TP -.B --socks-proxy server [port] +.B \-\-socks-proxy server [port] Connect to remote host through a Socks5 proxy at address .B server and port @@ -542,14 +542,14 @@ and port (default=1080). .\"********************************************************* .TP -.B --socks-proxy-retry +.B \-\-socks-proxy-retry Retry indefinitely on Socks proxy errors. If a Socks proxy error occurs, simulate a SIGUSR1 reset. .\"********************************************************* .TP -.B --resolv-retry n +.B \-\-resolv-retry n If hostname resolve fails for -.B --remote, +.B \-\-remote, retry resolve for .B n seconds before failing. @@ -559,18 +559,18 @@ Set to "infinite" to retry indefinitely. By default, -.B --resolv-retry infinite +.B \-\-resolv-retry infinite is enabled. You can disable by setting n=0. .\"********************************************************* .TP -.B --float +.B \-\-float Allow remote peer to change its IP address and/or port number, such as due to DHCP (this is the default if -.B --remote +.B \-\-remote is not used). -.B --float +.B \-\-float when specified with -.B --remote +.B \-\-remote allows an OpenVPN session to initially connect to a peer at a known address, however if packets arrive from a new address and pass all authentication tests, the new address @@ -579,14 +579,14 @@ you are connecting to a peer which holds a dynamic address such as a dial-in user or DHCP client. Essentially, -.B --float +.B \-\-float tells OpenVPN to accept authenticated packets from any address, not only the address which was specified in the -.B --remote +.B \-\-remote option. .\"********************************************************* .TP -.B --ipchange cmd +.B \-\-ipchange cmd Execute shell command .B cmd when our remote ip-address is initially authenticated or @@ -597,11 +597,11 @@ Execute as: .B cmd ip_address port_number Don't use -.B --ipchange +.B \-\-ipchange in -.B --mode server +.B \-\-mode server mode. Use a -.B --client-connect +.B \-\-client-connect script instead. See the "Environmental Variables" section below for @@ -636,41 +636,41 @@ reestablish a connection with its most recently authenticated peer on its new IP address. .\"********************************************************* .TP -.B --port port +.B \-\-port port TCP/UDP port number for both local and remote. The current default of 1194 represents the official IANA port number assignment for OpenVPN and has been used since version 2.0-beta17. Previous versions used port 5000 as the default. .\"********************************************************* .TP -.B --lport port +.B \-\-lport port TCP/UDP port number for bind. .\"********************************************************* .TP -.B --rport port +.B \-\-rport port TCP/UDP port number for remote. .\"********************************************************* .TP -.B --bind +.B \-\-bind Bind to local address and port. This is the default unless any of -.B --proto tcp-client +.B \-\-proto tcp-client , -.B --http-proxy +.B \-\-http-proxy or -.B --socks-proxy +.B \-\-socks-proxy are used. .\"********************************************************* .TP -.B --nobind +.B \-\-nobind Do not bind to local address and port. The IP stack will allocate a dynamic port for returning packets. Since the value of the dynamic port could not be known in advance by a peer, this option is only suitable for peers which will be initiating connections by using the -.B --remote +.B \-\-remote option. .\"********************************************************* .TP -.B --dev tunX | tapX | null +.B \-\-dev tunX | tapX | null TUN/TAP virtual network device ( .B X can be omitted for a dynamic device.) @@ -688,7 +688,7 @@ devices encapsulate IPv4 or IPv6 (OSI Layer 3) while devices encapsulate Ethernet 802.3 (OSI Layer 2). .\"********************************************************* .TP -.B --dev-type device-type +.B \-\-dev-type device-type Which device type are we using? .B device-type should be @@ -698,60 +698,60 @@ or .B tap (OSI Layer 2). Use this option only if the TUN/TAP device used with -.B --dev +.B \-\-dev does not begin with .B tun or .B tap. .\"********************************************************* .TP -.B --topology mode +.B \-\-topology mode Configure virtual addressing topology when running in -.B --dev tun +.B \-\-dev tun mode. This directive has no meaning in -.B --dev tap +.B \-\-dev tap mode, which always uses a .B subnet topology. If you set this directive on the server, the -.B --server +.B \-\-server and -.B --server-bridge +.B \-\-server-bridge directives will automatically push your chosen topology setting to clients as well. This directive can also be manually pushed to clients. Like the -.B --dev +.B \-\-dev directive, this directive must always be compatible between client and server. .B mode can be one of: -.B net30 -- +.B net30 \-\- Use a point-to-point topology, by allocating one /30 subnet per client. This is designed to allow point-to-point semantics when some or all of the connecting clients might be Windows systems. This is the default on OpenVPN 2.0. -.B p2p -- +.B p2p \-\- Use a point-to-point topology where the remote endpoint of the client's tun interface always points to the local endpoint of the server's tun interface. This mode allocates a single IP address per connecting client. Only use when none of the connecting clients are Windows systems. This mode is functionally equivalent to the -.B --ifconfig-pool-linear +.B \-\-ifconfig-pool-linear directive which is available in OpenVPN 2.0 and is now deprecated. -.B subnet -- +.B subnet \-\- Use a subnet rather than a point-to-point topology by configuring the tun interface with a local IP address and subnet mask, similar to the topology used in -.B --dev tap +.B \-\-dev tap and ethernet bridging mode. This mode allocates a single IP address per connecting client and works on Windows as well. Only available when server and clients are OpenVPN 2.1 or higher, or OpenVPN 2.0.x which has been manually patched with the -.B --topology +.B \-\-topology directive code. When used on Windows, requires version 8.2 or higher of the TAP-Win32 driver. When used on *nix, requires that the tun driver supports an @@ -761,26 +761,26 @@ command which sets a subnet instead of a remote endpoint IP address. This option exists in OpenVPN 2.1 or higher. .\"********************************************************* .TP -.B --tun-ipv6 +.B \-\-tun-ipv6 Build a tun link capable of forwarding IPv6 traffic. Should be used in conjunction with -.B --dev tun +.B \-\-dev tun or -.B --dev tunX. +.B \-\-dev tunX. A warning will be displayed if no specific IPv6 TUN support for your OS has been compiled into OpenVPN. .\"********************************************************* .TP -.B --dev-node node +.B \-\-dev-node node Explicitly set the device node rather than using /dev/net/tun, /dev/tun, /dev/tap, etc. If OpenVPN cannot figure out whether .B node is a TUN or TAP device based on the name, you should also specify -.B --dev-type tun +.B \-\-dev-type tun or -.B --dev-type tap. +.B \-\-dev-type tap. On Windows systems, select the TAP-Win32 adapter which is named @@ -788,24 +788,24 @@ is named in the Network Connections Control Panel or the raw GUID of the adapter enclosed by braces. The -.B --show-adapters +.B \-\-show-adapters option under Windows can also be used to enumerate all available TAP-Win32 adapters and will show both the network connections control panel name and the GUID for each TAP-Win32 adapter. .TP -.B --lladdr address +.B \-\-lladdr address Specify the link layer address, more commonly known as the MAC address. Only applied to TAP devices. .\"********************************************************* .TP -.B --iproute cmd +.B \-\-iproute cmd Set alternate command to execute instead of default iproute2 command. May be used in order to execute OpenVPN in unprivileged environment. .\"********************************************************* .TP -.B --ifconfig l rn +.B \-\-ifconfig l rn Set TUN/TAP adapter parameters. .B l is the IP address of the local VPN endpoint. @@ -820,7 +820,7 @@ which is being created or connected to. For TUN devices, which facilitate virtual point-to-point IP connections, the proper usage of -.B --ifconfig +.B \-\-ifconfig is to use two private IP addresses which are not a member of any existing subnet which is in use. @@ -834,7 +834,7 @@ you will be pinging across the VPN. For TAP devices, which provide the ability to create virtual ethernet segments, -.B --ifconfig +.B \-\-ifconfig is used to set an IP address and subnet mask just as a physical ethernet adapter would be @@ -855,42 +855,42 @@ standard interface to the different ifconfig implementations on different platforms. -.B --ifconfig +.B \-\-ifconfig parameters which are IP addresses can also be specified as a DNS or /etc/hosts file resolvable name. For TAP devices, -.B --ifconfig +.B \-\-ifconfig should not be used if the TAP interface will be getting an IP address lease from a DHCP server. .\"********************************************************* .TP -.B --ifconfig-noexec +.B \-\-ifconfig-noexec Don't actually execute ifconfig/netsh commands, instead pass -.B --ifconfig +.B \-\-ifconfig parameters to scripts using environmental variables. .\"********************************************************* .TP -.B --ifconfig-nowarn +.B \-\-ifconfig-nowarn Don't output an options consistency check warning if the -.B --ifconfig +.B \-\-ifconfig option on this side of the connection doesn't match the remote side. This is useful when you want to retain the overall benefits of the options consistency check (also see -.B --disable-occ +.B \-\-disable-occ option) while only disabling the ifconfig component of the check. For example, if you have a configuration where the local host uses -.B --ifconfig +.B \-\-ifconfig but the remote host does not, use -.B --ifconfig-nowarn +.B \-\-ifconfig-nowarn on the local host. This option will also silence warnings about potential @@ -898,7 +898,7 @@ address conflicts which occasionally annoy more experienced users by triggering "false positive" warnings. .\"********************************************************* .TP -.B --route network/IP [netmask] [gateway] [metric] +.B \-\-route network/IP [netmask] [gateway] [metric] Add route to routing table after connection is established. Multiple routes can be specified. Routes will be automatically torn down in reverse order prior to @@ -912,20 +912,20 @@ while at the same time providing portable semantics across OpenVPN's platform space. .B netmask -default -- 255.255.255.255 +default \-\- 255.255.255.255 .B gateway -default -- taken from -.B --route-gateway +default \-\- taken from +.B \-\-route-gateway or the second parameter to -.B --ifconfig +.B \-\-ifconfig when -.B --dev tun +.B \-\-dev tun is specified. .B metric -default -- taken from -.B --route-metric +default \-\- taken from +.B \-\-route-metric otherwise 0. The default can be specified by leaving an option blank or setting @@ -940,37 +940,37 @@ also be specified as a DNS or /etc/hosts file resolvable name, or as one of three special keywords: .B vpn_gateway --- The remote VPN endpoint address +\-\- The remote VPN endpoint address (derived either from -.B --route-gateway +.B \-\-route-gateway or the second parameter to -.B --ifconfig +.B \-\-ifconfig when -.B --dev tun +.B \-\-dev tun is specified). .B net_gateway --- The pre-existing IP default gateway, read from the routing +\-\- The pre-existing IP default gateway, read from the routing table (not supported on all OSes). .B remote_host --- The -.B --remote +\-\- The +.B \-\-remote address if OpenVPN is being run in client mode, and is undefined in server mode. .\"********************************************************* .TP -.B --max-routes n +.B \-\-max-routes n Allow a maximum number of n -.B --route +.B \-\-route options to be specified, either in the local configuration file, or pulled from an OpenVPN server. By default, n=100. .\"********************************************************* .TP -.B --route-gateway gw|'dhcp' +.B \-\-route-gateway gw|'dhcp' Specify a default gateway .B gw for use with -.B --route. +.B \-\-route. If .B dhcp @@ -979,14 +979,14 @@ the gateway address will be extracted from a DHCP negotiation with the OpenVPN server-side LAN. .\"********************************************************* .TP -.B --route-metric m +.B \-\-route-metric m Specify a default metric .B m for use with -.B --route. +.B \-\-route. .\"********************************************************* .TP -.B --route-delay [n] [w] +.B \-\-route-delay [n] [w] Delay .B n seconds (default=0) after connection @@ -994,16 +994,16 @@ establishment, before adding routes. If .B n is 0, routes will be added immediately upon connection establishment. If -.B --route-delay +.B \-\-route-delay is omitted, routes will be added immediately after TUN/TAP device open and -.B --up +.B \-\-up script execution, before any -.B --user +.B \-\-user or -.B --group +.B \-\-group privilege downgrade (or -.B --chroot +.B \-\-chroot execution.) This option is designed to be useful in scenarios where DHCP is @@ -1012,18 +1012,18 @@ tap adapter addresses. The delay will give the DHCP handshake time to complete before routes are added. On Windows, -.B --route-delay +.B \-\-route-delay tries to be more intelligent by waiting .B w seconds (w=30 by default) for the TAP-Win32 adapter to come up before adding routes. .\"********************************************************* .TP -.B --route-up cmd +.B \-\-route-up cmd Execute shell command .B cmd after routes are added, subject to -.B --route-delay. +.B \-\-route-delay. See the "Environmental Variables" section below for additional parameters passed as environmental variables. @@ -1033,17 +1033,17 @@ Note that can be a shell command with multiple arguments. .\"********************************************************* .TP -.B --route-noexec +.B \-\-route-noexec Don't add or remove routes automatically. Instead pass routes to -.B --route-up +.B \-\-route-up script using environmental variables. .\"********************************************************* .TP -.B --route-nopull +.B \-\-route-nopull When used with -.B --client +.B \-\-client or -.B --pull, +.B \-\-pull, accept options pushed by server EXCEPT for routes. When used on the client, this option effectively bars the @@ -1052,16 +1052,16 @@ however note that this option still allows the server to set the TCP/IP properties of the client's TUN/TAP interface. .\"********************************************************* .TP -.B --allow-pull-fqdn +.B \-\-allow-pull-fqdn Allow client to pull DNS names from server (rather than being limited to IP address) for -.B --ifconfig, -.B --route, +.B \-\-ifconfig, +.B \-\-route, and -.B --route-gateway. +.B \-\-route-gateway. .\"********************************************************* .TP -.B --redirect-gateway flags... +.B \-\-redirect-gateway flags... (Experimental) Automatically execute routing commands to cause all outgoing IP traffic to be redirected over the VPN. @@ -1069,7 +1069,7 @@ This option performs three steps: .B (1) Create a static route for the -.B --remote +.B \-\-remote address which forwards to the pre-existing default gateway. This is done so that .B (3) @@ -1080,11 +1080,11 @@ Delete the default gateway route. .B (3) Set the new default gateway to be the VPN endpoint address (derived either from -.B --route-gateway +.B \-\-route-gateway or the second parameter to -.B --ifconfig +.B \-\-ifconfig when -.B --dev tun +.B \-\-dev tun is specified). When the tunnel is torn down, all of the above steps are reversed so @@ -1092,7 +1092,7 @@ that the original default route is restored. Option flags: -.B local -- +.B local \-\- Add the .B local flag if both OpenVPN servers are directly connected via a common subnet, @@ -1102,19 +1102,19 @@ flag will cause step .B 1 above to be omitted. -.B def1 -- +.B def1 \-\- Use this flag to override the default gateway by using 0.0.0.0/1 and 128.0.0.0/1 rather than 0.0.0.0/0. This has the benefit of overriding but not wiping out the original default gateway. -.B bypass-dhcp -- +.B bypass-dhcp \-\- Add a direct route to the DHCP server (if it is non-local) which bypasses the tunnel (Available on Windows clients, may not be available on non-Windows clients). -.B bypass-dns -- +.B bypass-dns \-\- Add a direct route to the DNS server(s) (if they are non-local) which bypasses the tunnel (Available on Windows clients, may not be available @@ -1123,13 +1123,13 @@ on non-Windows clients). Using the def1 flag is highly recommended. .\"********************************************************* .TP -.B --link-mtu n +.B \-\-link-mtu n Sets an upper bound on the size of UDP packets which are sent between OpenVPN peers. It's best not to set this parameter unless you know what you're doing. .\"********************************************************* .TP -.B --tun-mtu n +.B \-\-tun-mtu n Take the TUN device MTU to be .B n and derive the link MTU @@ -1145,17 +1145,17 @@ MTU problems often manifest themselves as connections which hang during periods of active usage. It's best to use the -.B --fragment +.B \-\-fragment and/or -.B --mssfix +.B \-\-mssfix options to deal with MTU sizing issues. .\"********************************************************* .TP -.B --tun-mtu-extra n +.B \-\-tun-mtu-extra n Assume that the TUN/TAP device might return as many as .B n bytes more than the -.B --tun-mtu +.B \-\-tun-mtu size on read. This parameter defaults to 0, which is sufficient for most TUN devices. TAP devices may introduce additional overhead in excess of the MTU size, and a setting of 32 is the default when TAP devices are used. @@ -1163,34 +1163,34 @@ This parameter only controls internal OpenVPN buffer sizing, so there is no transmission overhead associated with using a larger value. .\"********************************************************* .TP -.B --mtu-disc type +.B \-\-mtu-disc type Should we do Path MTU discovery on TCP/UDP channel? Only supported on OSes such as Linux that supports the necessary system call to set. .B 'no' --- Never send DF (Don't Fragment) frames +\-\- Never send DF (Don't Fragment) frames .br .B 'maybe' --- Use per-route hints +\-\- Use per-route hints .br .B 'yes' --- Always DF (Don't Fragment) +\-\- Always DF (Don't Fragment) .br .\"********************************************************* .TP -.B --mtu-test +.B \-\-mtu-test To empirically measure MTU on connection startup, add the -.B --mtu-test +.B \-\-mtu-test option to your configuration. OpenVPN will send ping packets of various sizes to the remote peer and measure the largest packets which were successfully received. The -.B --mtu-test +.B \-\-mtu-test process normally takes about 3 minutes to complete. .\"********************************************************* .TP -.B --fragment max +.B \-\-fragment max Enable internal datagram fragmentation so that no UDP datagrams are sent which are larger than @@ -1200,24 +1200,24 @@ bytes. The .B max parameter is interpreted in the same way as the -.B --link-mtu +.B \-\-link-mtu parameter, i.e. the UDP packet size after encapsulation overhead has been added in, but not including the UDP header itself. The -.B --fragment +.B \-\-fragment option only makes sense when you are using the UDP protocol ( -.B --proto udp +.B \-\-proto udp ). -.B --fragment +.B \-\-fragment adds 4 bytes of overhead per datagram. See the -.B --mssfix +.B \-\-mssfix option below for an important related option to -.B --fragment. +.B \-\-fragment. It should also be noted that this option is not meant to replace UDP fragmentation at the IP stack level. It is only meant as a @@ -1230,44 +1230,45 @@ internal fragmentation capability may be your only option, such as tunneling a UDP multicast stream which requires fragmentation. .\"********************************************************* .TP -.B --mssfix max +.B \-\-mssfix max Announce to TCP sessions running over the tunnel that they should limit their send packet sizes such that after OpenVPN has encapsulated them, the resulting UDP packet size that OpenVPN sends to its peer will not exceed .B max -bytes. +bytes. The default value is +.B 1450. The .B max parameter is interpreted in the same way as the -.B --link-mtu +.B \-\-link-mtu parameter, i.e. the UDP packet size after encapsulation overhead has been added in, but not including the UDP header itself. The -.B --mssfix +.B \-\-mssfix option only makes sense when you are using the UDP protocol for OpenVPN peer-to-peer communication, i.e. -.B --proto udp. +.B \-\-proto udp. -.B --mssfix +.B \-\-mssfix and -.B --fragment +.B \-\-fragment can be ideally used together, where -.B --mssfix +.B \-\-mssfix will try to keep TCP from needing packet fragmentation in the first place, and if big packets come through anyhow (from protocols other than TCP), -.B --fragment +.B \-\-fragment will internally fragment them. Both -.B --fragment +.B \-\-fragment and -.B --mssfix +.B \-\-mssfix are designed to work around cases where Path MTU discovery is broken on the network path between OpenVPN peers. @@ -1276,35 +1277,35 @@ connection which successfully starts, but then stalls during active usage. If -.B --fragment +.B \-\-fragment and -.B --mssfix +.B \-\-mssfix are used together, -.B --mssfix +.B \-\-mssfix will take its default .B max parameter from the -.B --fragment max +.B \-\-fragment max option. Therefore, one could lower the maximum UDP packet size to 1300 (a good first try for solving MTU-related connection problems) with the following options: -.B --tun-mtu 1500 --fragment 1300 --mssfix +.B \-\-tun-mtu 1500 \-\-fragment 1300 \-\-mssfix .\"********************************************************* .TP -.B --sndbuf size +.B \-\-sndbuf size Set the TCP/UDP socket send buffer size. Currently defaults to 65536 bytes. .\"********************************************************* .TP -.B --rcvbuf size +.B \-\-rcvbuf size Set the TCP/UDP socket receive buffer size. Currently defaults to 65536 bytes. .\"********************************************************* .TP -.B --socket-flags flags... +.B \-\-socket-flags flags... Apply the given flags to the OpenVPN transport socket. Currently, only .B TCP_NODELAY @@ -1321,12 +1322,12 @@ This option is pushable from server to client, and should be used on both client and server for maximum effect. .\"********************************************************* .TP -.B --txqueuelen n +.B \-\-txqueuelen n (Linux only) Set the TX queue length on the TUN/TAP interface. Currently defaults to 100. .\"********************************************************* .TP -.B --shaper n +.B \-\-shaper n Limit bandwidth of outgoing tunnel data to .B n bytes per second on the TCP/UDP port. @@ -1362,7 +1363,7 @@ OpenVPN allows to be between 100 bytes/sec and 100 Mbytes/sec. .\"********************************************************* .TP -.B --inactive n [bytes] +.B \-\-inactive n [bytes] Causes OpenVPN to exit after .B n seconds of inactivity on the TUN/TAP device. The time length @@ -1376,18 +1377,18 @@ produces a combined in/out byte count that is less than .B bytes. .\"********************************************************* .TP -.B --ping n +.B \-\-ping n Ping remote over the TCP/UDP control channel if no packets have been sent for at least .B n seconds (specify -.B --ping +.B \-\-ping on both peers to cause ping packets to be sent in both directions since OpenVPN ping packets are not echoed like IP ping packets). When used in one of OpenVPN's secure modes (where -.B --secret, --tls-server, +.B \-\-secret, \-\-tls-server, or -.B --tls-client +.B \-\-tls-client is specified), the ping packet will be cryptographically secure. @@ -1400,33 +1401,33 @@ pass will not time out. (2) To provide a basis for the remote to test the existence of its peer using the -.B --ping-exit +.B \-\-ping-exit option. .\"********************************************************* .TP -.B --ping-exit n +.B \-\-ping-exit n Causes OpenVPN to exit after .B n seconds pass without reception of a ping or other packet from remote. This option can be combined with -.B --inactive, --ping, +.B \-\-inactive, \-\-ping, and -.B --ping-exit +.B \-\-ping-exit to create a two-tiered inactivity disconnect. For example, -.B openvpn [options...] --inactive 3600 --ping 10 --ping-exit 60 +.B openvpn [options...] \-\-inactive 3600 \-\-ping 10 \-\-ping-exit 60 when used on both peers will cause OpenVPN to exit within 60 seconds if its peer disconnects, but will exit after one hour if no actual tunnel data is exchanged. .\"********************************************************* .TP -.B --ping-restart n +.B \-\-ping-restart n Similar to -.B --ping-exit, +.B \-\-ping-exit, but trigger a .B SIGUSR1 restart after @@ -1445,13 +1446,13 @@ as If the peer cannot be reached, a restart will be triggered, causing the hostname used with -.B --remote +.B \-\-remote to be re-resolved (if -.B --resolv-retry +.B \-\-resolv-retry is also specified). In server mode, -.B --ping-restart, --inactive, +.B \-\-ping-restart, \-\-inactive, or any other type of internally generated signal will always be applied to individual client instance objects, never to whole server itself. @@ -1460,14 +1461,14 @@ which would normally cause a restart, will cause the deletion of the client instance object instead. In client mode, the -.B --ping-restart +.B \-\-ping-restart parameter is set to 120 seconds by default. This default will hold until the client pulls a replacement value from the server, based on the -.B --keepalive +.B \-\-keepalive setting in the server configuration. To disable the 120 second default, set -.B --ping-restart 0 +.B \-\-ping-restart 0 on the client. See the signals section below for more information @@ -1477,27 +1478,27 @@ on Note that the behavior of .B SIGUSR1 can be modified by the -.B --persist-tun, --persist-key, --persist-local-ip, +.B \-\-persist-tun, \-\-persist-key, \-\-persist-local-ip, and -.B --persist-remote-ip +.B \-\-persist-remote-ip options. Also note that -.B --ping-exit +.B \-\-ping-exit and -.B --ping-restart +.B \-\-ping-restart are mutually exclusive and cannot be used together. .\"********************************************************* .TP -.B --keepalive n m +.B \-\-keepalive n m A helper directive designed to simplify the expression of -.B --ping +.B \-\-ping and -.B --ping-restart +.B \-\-ping-restart in server mode configurations. For example, -.B --keepalive 10 60 +.B \-\-keepalive 10 60 expands as follows: .nf @@ -1516,24 +1517,24 @@ expands as follows: .fi .\"********************************************************* .TP -.B --ping-timer-rem +.B \-\-ping-timer-rem Run the -.B --ping-exit +.B \-\-ping-exit / -.B --ping-restart +.B \-\-ping-restart timer only if we have a remote address. Use this option if you are starting the daemon in listen mode (i.e. without an explicit -.B --remote +.B \-\-remote peer), and you don't want to start clocking timeouts until a remote peer connects. .\"********************************************************* .TP -.B --persist-tun +.B \-\-persist-tun Don't close and reopen TUN/TAP device or run up/down scripts across .B SIGUSR1 or -.B --ping-restart +.B \-\-ping-restart restarts. .B SIGUSR1 @@ -1543,14 +1544,14 @@ but which offers finer-grained control over reset options. .\"********************************************************* .TP -.B --persist-key +.B \-\-persist-key Don't re-read key files across .B SIGUSR1 or -.B --ping-restart. +.B \-\-ping-restart. This option can be combined with -.B --user nobody +.B \-\-user nobody to allow restarts triggered by the .B SIGUSR1 signal. @@ -1563,29 +1564,29 @@ This option solves the problem by persisting keys across resets, so they don't need to be re-read. .\"********************************************************* .TP -.B --persist-local-ip +.B \-\-persist-local-ip Preserve initially resolved local IP address and port number across .B SIGUSR1 or -.B --ping-restart +.B \-\-ping-restart restarts. .\"********************************************************* .TP -.B --persist-remote-ip +.B \-\-persist-remote-ip Preserve most recently authenticated remote IP address and port number across .B SIGUSR1 or -.B --ping-restart +.B \-\-ping-restart restarts. .\"********************************************************* .TP -.B --mlock +.B \-\-mlock Disable paging by calling the POSIX mlockall function. Requires that OpenVPN be initially run as root (though OpenVPN can subsequently downgrade its UID using the -.B --user +.B \-\-user option). Using this option ensures that key material and tunnel @@ -1597,33 +1598,33 @@ would not be able to scan the system swap file to recover previously used ephemeral keys, which are used for a period of time governed by the -.B --reneg +.B \-\-reneg options (see below), then are discarded. The downside of using -.B --mlock +.B \-\-mlock is that it will reduce the amount of physical memory available to other applications. .\"********************************************************* .TP -.B --up cmd +.B \-\-up cmd Shell command to run after successful TUN/TAP device open (pre -.B --user +.B \-\-user UID change). The up script is useful for specifying route commands which route IP traffic destined for private subnets which exist at the other end of the VPN connection into the tunnel. For -.B --dev tun +.B \-\-dev tun execute as: .B cmd tun_dev tun_mtu link_mtu ifconfig_local_ip ifconfig_remote_ip [ init | restart ] For -.B --dev tap +.B \-\-dev tap execute as: .B cmd tap_dev tap_mtu link_mtu ifconfig_local_ip ifconfig_netmask [ init | restart ] @@ -1648,62 +1649,62 @@ In this context, the last command line parameter passed to the script will be .I init. If the -.B --up-restart +.B \-\-up-restart option is also used, the up script will be called for restarts as well. A restart is considered to be a partial reinitialization of OpenVPN where the TUN/TAP instance is preserved (the -.B --persist-tun +.B \-\-persist-tun option will enable such preservation). A restart can be generated by a SIGUSR1 signal, a -.B --ping-restart +.B \-\-ping-restart timeout, or a connection reset when the TCP protocol is enabled with the -.B --proto +.B \-\-proto option. If a restart occurs, and -.B --up-restart +.B \-\-up-restart has been specified, the up script will be called with .I restart as the last parameter. The following standalone example shows how the -.B --up +.B \-\-up script can be called in both an initialization and restart context. (NOTE: for security reasons, don't run the following example unless UDP port 9999 is blocked by your firewall. Also, the example will run indefinitely, so you should abort with control-c). -.B openvpn --dev tun --port 9999 --verb 4 --ping-restart 10 --up 'echo up' --down 'echo down' --persist-tun --up-restart +.B openvpn \-\-dev tun \-\-port 9999 \-\-verb 4 \-\-ping-restart 10 \-\-up 'echo up' \-\-down 'echo down' \-\-persist-tun \-\-up-restart Note that OpenVPN also provides the -.B --ifconfig +.B \-\-ifconfig option to automatically ifconfig the TUN device, eliminating the need to define an -.B --up +.B \-\-up script, unless you also want to configure routes in the -.B --up +.B \-\-up script. If -.B --ifconfig +.B \-\-ifconfig is also specified, OpenVPN will pass the ifconfig local and remote endpoints on the command line to the -.B --up +.B \-\-up script so that they can be used to configure routes such as: .B route add -net 10.0.0.0 netmask 255.255.255.0 gw $5 .\"********************************************************* .TP -.B --up-delay +.B \-\-up-delay Delay TUN/TAP open and possible -.B --up +.B \-\-up script execution until after TCP/UDP connection establishment with peer. In -.B --proto udp +.B \-\-proto udp mode, this option normally requires the use of -.B --ping +.B \-\-ping to allow connection initiation to be sensed in the absence of tunnel data, since UDP is a "connectionless" protocol. @@ -1712,50 +1713,50 @@ transitioning to "connected" until connection establishment, i.e. the receipt of the first authenticated packet from the peer. .\"********************************************************* .TP -.B --down cmd +.B \-\-down cmd Shell command to run after TUN/TAP device close (post -.B --user +.B \-\-user UID change and/or -.B --chroot +.B \-\-chroot ). Called with the same parameters and environmental variables as the -.B --up +.B \-\-up option above. Note that if you reduce privileges by using -.B --user +.B \-\-user and/or -.B --group, +.B \-\-group, your -.B --down +.B \-\-down script will also run at reduced privilege. .\"********************************************************* .TP -.B --down-pre +.B \-\-down-pre Call -.B --down +.B \-\-down cmd/script before, rather than after, TUN/TAP close. .\"********************************************************* .TP -.B --up-restart +.B \-\-up-restart Enable the -.B --up +.B \-\-up and -.B --down +.B \-\-down scripts to be called for restarts as well as initial program start. This option is described more fully above in the -.B --up +.B \-\-up option documentation. .\"********************************************************* .TP -.B --setenv name value +.B \-\-setenv name value Set a custom environmental variable .B name=value to pass to script. .\"********************************************************* .TP -.B --setenv FORWARD_COMPATIBLE 1 +.B \-\-setenv FORWARD_COMPATIBLE 1 Relax config file syntax checking so that unknown directives will trigger a warning but not a fatal error, on the assumption that a given unknown directive might be valid @@ -1768,7 +1769,7 @@ new software features to gracefully degrade when encountered by older software versions. .\"********************************************************* .TP -.B --setenv-safe name value +.B \-\-setenv-safe name value Set a custom environmental variable .B OPENVPN_name=value to pass to script. @@ -1779,23 +1780,23 @@ is a safety precaution to prevent a LD_PRELOAD style attack from a malicious or compromised server. .\"********************************************************* .TP -.B --script-security level [method] +.B \-\-script-security level [method] This directive offers policy-level control over OpenVPN's usage of external programs and scripts. Lower .B level values are more restrictive, higher values are more permissive. Settings for .B level: -.B 0 -- +.B 0 \-\- Strictly no calling of external programs. .br -.B 1 -- +.B 1 \-\- (Default) Only call built-in executables such as ifconfig, ip, route, or netsh. .br -.B 2 -- +.B 2 \-\- Allow calling of built-in executables and user-defined scripts. .br -.B 3 -- +.B 3 \-\- Allow passwords to be passed to scripts via environmental variables (potentially unsafe). The @@ -1804,33 +1805,33 @@ parameter indicates how OpenVPN should call external commands and scripts. Settings for .B method: -.B execve -- +.B execve \-\- (default) Use execve() function on Unix family OSes and CreateProcess() on Windows. .br -.B system -- +.B system \-\- Use system() function (deprecated and less safe since the external program command line is subject to shell expansion). The -.B --script-security +.B \-\-script-security option was introduced in OpenVPN 2.1_rc9. For configuration file compatibility with previous OpenVPN versions, use: -.B --script-security 3 system +.B \-\-script-security 3 system .\"********************************************************* .TP -.B --disable-occ +.B \-\-disable-occ Don't output a warning message if option inconsistencies are detected between peers. An example of an option inconsistency would be where one peer uses -.B --dev tun +.B \-\-dev tun while the other peer uses -.B --dev tap. +.B \-\-dev tap. Use of this option is discouraged, but is provided as a temporary fix in situations where a recent version of OpenVPN must connect to an old version. .\"********************************************************* .TP -.B --user user +.B \-\-user user Change the user ID of the OpenVPN process to .B user after initialization, dropping privileges in the process. @@ -1852,7 +1853,7 @@ you want to reset an OpenVPN daemon with a signal (for example in response to a DHCP reset), you should make use of one or more of the -.B --persist +.B \-\-persist options to ensure that OpenVPN doesn't need to execute any privileged operations in order to restart (such as re-reading key files or running @@ -1860,16 +1861,16 @@ or running on the TUN device). .\"********************************************************* .TP -.B --group group +.B \-\-group group Similar to the -.B --user +.B \-\-user option, this option changes the group ID of the OpenVPN process to .B group after initialization. .\"********************************************************* .TP -.B --cd dir +.B \-\-cd dir Change directory to .B dir prior to reading any files such as @@ -1881,16 +1882,16 @@ to the current directory such as "." or "..". This option is useful when you are running OpenVPN in -.B --daemon +.B \-\-daemon mode, and you want to consolidate all of your OpenVPN control files in one location. .\"********************************************************* .TP -.B --chroot dir +.B \-\-chroot dir Chroot to .B dir after initialization. -.B --chroot +.B \-\-chroot essentially redefines .B dir as being the top @@ -1909,22 +1910,22 @@ complications can result when scripts or restarts are executed after the chroot operation. .\"********************************************************* .TP -.B --setcon context +.B \-\-setcon context Apply SELinux .B context after initialization. This essentially provides the ability to restrict OpenVPN's rights to only network I/O operations, thanks to SELinux. This goes further than -.B --user +.B \-\-user and -.B --chroot +.B \-\-chroot in that those two, while being great security features, unfortunately do not protect against privilege escalation by exploitation of a vulnerable system call. You can of course combine all three, but please note that since setcon requires access to /proc you will have to provide -it inside the chroot directory (e.g. with mount --bind). +it inside the chroot directory (e.g. with mount \-\-bind). Since the setcon operation is delayed until after initialization, OpenVPN can be restricted to just @@ -1936,13 +1937,13 @@ allow many things required only during initialization. Like with chroot, complications can result when scripts or restarts are executed after the setcon operation, which is why you should really consider using the -.B --persist-key +.B \-\-persist-key and -.B --persist-tun +.B \-\-persist-tun options. .\"********************************************************* .TP -.B --daemon [progname] +.B \-\-daemon [progname] Become a daemon after all initialization functions are completed. This option will cause all message and error output to be sent to the syslog file (such as /var/log/messages), @@ -1951,10 +1952,10 @@ ifconfig commands, which will go to /dev/null unless otherwise redirected. The syslog redirection occurs immediately at the point that -.B --daemon +.B \-\-daemon is parsed on the command line even though the daemonization point occurs later. If one of the -.B --log +.B \-\-log options is present, it will supercede syslog redirection. @@ -1970,7 +1971,7 @@ When unspecified, defaults to "openvpn". When OpenVPN is run with the -.B --daemon +.B \-\-daemon option, it will try to delay daemonization until the majority of initialization functions which are capable of generating fatal errors are complete. This means that initialization scripts can test the return status of the @@ -1980,20 +1981,20 @@ has correctly initialized and entered the packet forwarding event loop. In OpenVPN, the vast majority of errors which occur after initialization are non-fatal. .\"********************************************************* .TP -.B --syslog [progname] +.B \-\-syslog [progname] Direct log output to system logger, but do not become a daemon. See -.B --daemon +.B \-\-daemon directive above for description of .B progname parameter. .\"********************************************************* .TP -.B --passtos +.B \-\-passtos Set the TOS field of the tunnel packet to what the payload's TOS is. .\"********************************************************* .TP -.B --inetd [wait|nowait] [progname] +.B \-\-inetd [wait|nowait] [progname] Use this option when OpenVPN is being run from the inetd or .BR xinetd(8) server. @@ -2004,7 +2005,7 @@ option must match what is specified in the inetd/xinetd config file. The .B nowait mode can only be used with -.B --proto tcp-server. +.B \-\-proto tcp-server. The default is .B wait. The @@ -2016,16 +2017,16 @@ see the OpenVPN FAQ: .I http://openvpn.net/faq.html#oneport This option precludes the use of -.B --daemon, --local, +.B \-\-daemon, \-\-local, or -.B --remote. +.B \-\-remote. Note that this option causes message and error output to be handled in the same way as the -.B --daemon +.B \-\-daemon option. The optional .B progname parameter is also handled exactly as in -.B --daemon. +.B \-\-daemon. Also note that in .B wait @@ -2035,7 +2036,7 @@ on using OpenVPN with xinetd: .I http://openvpn.net/1xhowto.html .\"********************************************************* .TP -.B --log file +.B \-\-log file Output logging messages to .B file, including output to stdout/stderr which @@ -2046,44 +2047,44 @@ already exists it will be truncated. This option takes effect immediately when it is parsed in the command line and will supercede syslog output if -.B --daemon +.B \-\-daemon or -.B --inetd +.B \-\-inetd is also specified. This option is persistent over the entire course of an OpenVPN instantiation and will not be reset by SIGHUP, SIGUSR1, or -.B --ping-restart. +.B \-\-ping-restart. Note that on Windows, when OpenVPN is started as a service, logging occurs by default without the need to specify this option. .\"********************************************************* .TP -.B --log-append file +.B \-\-log-append file Append logging messages to .B file. If .B file does not exist, it will be created. This option behaves exactly like -.B --log +.B \-\-log except that it appends to rather than truncating the log file. .\"********************************************************* .TP -.B --suppress-timestamps +.B \-\-suppress-timestamps Avoid writing timestamps to log messages, even when they otherwise would be prepended. In particular, this applies to log messages sent to stdout. .\"********************************************************* .TP -.B --writepid file +.B \-\-writepid file Write OpenVPN's main process ID to .B file. .\"********************************************************* .TP -.B --nice n +.B \-\-nice n Change process priority after initialization ( .B n @@ -2092,14 +2093,14 @@ greater than 0 is lower priority, less than zero is higher priority). .\"********************************************************* .\".TP -.\".B --nice-work n +.\".B \-\-nice-work n .\"Change priority of background TLS work thread. The TLS thread .\"feature is enabled when OpenVPN is built .\"with pthread support, and you are running OpenVPN .\"in TLS mode (i.e. with -.\".B --tls-client +.\".B \-\-tls-client .\"or -.\".B --tls-server +.\".B \-\-tls-server .\"specified). .\" .\"Using a TLS thread offloads the CPU-intensive process of SSL/TLS-based @@ -2109,12 +2110,12 @@ less than zero is higher priority). .\"The parameter .\".B n .\"is interpreted exactly as with the -.\".B --nice +.\".B \-\-nice .\"option above, but in relation to the work thread rather .\"than the main thread. .\"********************************************************* .TP -.B --fast-io +.B \-\-fast-io (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to poll/epoll/select prior to the write operation. The purpose of such a call would normally be to block until the device @@ -2125,13 +2126,13 @@ by avoiding the poll/epoll/select call, improving CPU efficiency by 5% to 10%. This option can only be used on non-Windows systems, when -.B --proto udp +.B \-\-proto udp is specified, and when -.B --shaper +.B \-\-shaper is NOT specified. .\"********************************************************* .TP -.B --multihome +.B \-\-multihome Configure a multi-homed UDP server. This option can be used when OpenVPN has been configured to listen on all interfaces, and will attempt to bind client sessions to the interface on which packets @@ -2140,13 +2141,13 @@ of the same interface. Note that this option is only relevant for UDP servers and currently is only implemented on Linux. Note: clients connecting to a -.B --multihome +.B \-\-multihome server should always use the -.B --nobind +.B \-\-nobind option. .\"********************************************************* .TP -.B --echo [parms...] +.B \-\-echo [parms...] Echo .B parms to log output. @@ -2155,7 +2156,7 @@ Designed to be used to send messages to a controlling application which is receiving the OpenVPN log output. .\"********************************************************* .TP -.B --remap-usr1 signal +.B \-\-remap-usr1 signal Control whether internally or externally generated SIGUSR1 signals are remapped to SIGHUP (restart without persisting state) or @@ -2166,20 +2167,20 @@ can be set to "SIGHUP" or "SIGTERM". By default, no remapping occurs. .\"********************************************************* .TP -.B --verb n +.B \-\-verb n Set output verbosity to .B n (default=1). Each level shows all info from the previous levels. Level 3 is recommended if you want a good summary of what's happening without being swamped by output. -.B 0 -- +.B 0 \-\- No output except fatal errors. .br -.B 1 to 4 -- +.B 1 to 4 \-\- Normal usage range. .br -.B 5 -- +.B 5 \-\- Output .B R and @@ -2187,12 +2188,12 @@ and characters to the console for each packet read and write, uppercase is used for TCP/UDP packets and lowercase is used for TUN/TAP packets. .br -.B 6 to 11 -- +.B 6 to 11 \-\- Debug info range (see errlevel.h for additional information on debug levels). .\"********************************************************* .TP -.B --status file [n] +.B \-\-status file [n] Write operational status to .B file every @@ -2204,21 +2205,21 @@ Status can also be written to the syslog by sending a signal. .\"********************************************************* .TP -.B --status-version [n] +.B \-\-status-version [n] Choose the status file format version number. Currently .B n can be 1, 2, or 3 and defaults to 1. .\"********************************************************* .TP -.B --mute n +.B \-\-mute n Log at most .B n consecutive messages in the same category. This is useful to limit repetitive logging of similar message types. .\"********************************************************* .TP -.B --comp-lzo [mode] -Use fast LZO compression -- may add up to 1 byte per +.B \-\-comp-lzo [mode] +Use fast LZO compression \-\- may add up to 1 byte per packet for incompressible data. .B mode may be "yes", "no", or "adaptive" (default). @@ -2228,16 +2229,16 @@ compression on or off for individual clients. First, make sure the client-side config file enables selective compression by having at least one -.B --comp-lzo +.B \-\-comp-lzo directive, such as -.B --comp-lzo no. +.B \-\-comp-lzo no. This will turn off compression by default, but allow a future directive push from the server to dynamically change the on/off/adaptive setting. Next in a -.B --client-config-dir +.B \-\-client-config-dir file, specify the compression setting for the client, for example: @@ -2256,12 +2257,12 @@ setting for the server side of the link, the second sets the client side. .\"********************************************************* .TP -.B --comp-noadapt +.B \-\-comp-noadapt When used in conjunction with -.B --comp-lzo, +.B \-\-comp-lzo, this option will disable OpenVPN's adaptive compression algorithm. Normally, adaptive compression is enabled with -.B --comp-lzo. +.B \-\-comp-lzo. Adaptive compression tries to optimize the case where you have compression enabled, but you are sending predominantly uncompressible @@ -2273,7 +2274,7 @@ the compression efficiency will be very low, triggering openvpn to disable compression for a period of time until the next re-sample test. .\"********************************************************* .TP -.B --management IP port [pw-file] +.B \-\-management IP port [pw-file] Enable a TCP server on .B IP:port to handle daemon management functions. @@ -2292,9 +2293,9 @@ and set .B port to 'unix'. While the default behavior is to create a unix domain socket that may be connected to by any process, the -.B --management-client-user +.B \-\-management-client-user and -.B --management-client-group +.B \-\-management-client-group directives can be used to restrict access. The management interface provides a special mode where the TCP @@ -2323,24 +2324,24 @@ be set to 127.0.0.1 server to local clients. .\"********************************************************* .TP -.B --management-query-passwords +.B \-\-management-query-passwords Query management channel for private key password and -.B --auth-user-pass +.B \-\-auth-user-pass username/password. Only query the management channel for inputs which ordinarily would have been queried from the console. .\"********************************************************* .TP -.B --management-forget-disconnect +.B \-\-management-forget-disconnect Make OpenVPN forget passwords when management session disconnects. This directive does not affect the -.B --http-proxy +.B \-\-http-proxy username/password. It is always cached. .\"********************************************************* .TP -.B --management-hold +.B \-\-management-hold Start OpenVPN in a hibernating state, until a client of the management interface explicitly starts it with the @@ -2348,45 +2349,45 @@ with the command. .\"********************************************************* .TP -.B --management-signal +.B \-\-management-signal Send SIGUSR1 signal to OpenVPN if management session disconnects. This is useful when you wish to disconnect an OpenVPN session on user logoff. .\"********************************************************* .TP -.B --management-log-cache n +.B \-\-management-log-cache n Cache the most recent .B n lines of log file history for usage by the management channel. .\"********************************************************* .TP -.B --management-client-auth +.B \-\-management-client-auth Gives management interface client the responsibility to authenticate clients after their client certificate has been verified. See management-notes.txt in OpenVPN distribution for detailed notes. .\"********************************************************* .TP -.B --management-client-pf +.B \-\-management-client-pf Management interface clients must specify a packet filter file for each connecting client. See management-notes.txt in OpenVPN distribution for detailed notes. .\"********************************************************* .TP -.B --management-client-user u +.B \-\-management-client-user u When the management interface is listening on a unix domain socket, only allow connections from user .B u. .\"********************************************************* .TP -.B --management-client-group g +.B \-\-management-client-group g When the management interface is listening on a unix domain socket, only allow connections from group .B g. .\"********************************************************* .TP -.B --plugin module-pathname [init-string] +.B \-\-plugin module-pathname [init-string] Load plug-in module from the file .B module-pathname, passing @@ -2422,7 +2423,7 @@ the connection to be authenticated. .SS Server Mode Starting with OpenVPN 2.0, a multi-client TCP/UDP server mode is supported, and can be enabled with the -.B --mode server +.B \-\-mode server option. In server mode, OpenVPN will listen on a single port for incoming client connections. All client connections will be routed through a single tun or tap @@ -2432,7 +2433,7 @@ on sufficiently fast hardware. SSL/TLS authentication must be used in this mode. .\"********************************************************* .TP -.B --server network netmask +.B \-\-server network netmask A helper directive designed to simplify the configuration of OpenVPN's server mode. This directive will set up an OpenVPN server which will allocate addresses to clients @@ -2442,7 +2443,7 @@ for use as the server-side endpoint of the local TUN/TAP interface. For example, -.B --server 10.8.0.0 255.255.255.0 +.B \-\-server 10.8.0.0 255.255.255.0 expands as follows: .nf @@ -2472,23 +2473,23 @@ expands as follows: .fi Don't use -.B --server +.B \-\-server if you are ethernet bridging. Use -.B --server-bridge +.B \-\-server-bridge instead. .\"********************************************************* .TP -.B --server-bridge gateway netmask pool-start-IP pool-end-IP +.B \-\-server-bridge gateway netmask pool-start-IP pool-end-IP .TP -.B --server-bridge ['nogw'] +.B \-\-server-bridge ['nogw'] A helper directive similar to -.B --server +.B \-\-server which is designed to simplify the configuration of OpenVPN's server mode in ethernet bridging configurations. If -.B --server-bridge +.B \-\-server-bridge is used without any parameters, it will enable a DHCP-proxy mode, where connecting OpenVPN clients will receive an IP address for their TAP adapter from the DHCP server running @@ -2516,7 +2517,7 @@ IP/netmask on the bridge interface. The and .B netmask parameters to -.B --server-bridge +.B \-\-server-bridge can be set to either the IP/netmask of the bridge interface, or the IP/netmask of the default gateway/router on the bridged @@ -2548,7 +2549,7 @@ push "route-gateway 10.8.0.4" .fi In another example, -.B --server-bridge +.B \-\-server-bridge (without parameters) expands as follows: .nf @@ -2563,7 +2564,7 @@ push "route-gateway dhcp" .fi Or -.B --server-bridge nogw +.B \-\-server-bridge nogw expands as follows: .nf @@ -2576,13 +2577,13 @@ tls-server .fi .\"********************************************************* .TP -.B --push "option" +.B \-\-push "option" Push a config file option back to the client for remote execution. Note that .B option must be enclosed in double quotes (""). The client must specify -.B --pull +.B \-\-pull in its config file. The set of options which can be pushed is limited by both feasibility and security. Some options such as those which would execute scripts @@ -2593,44 +2594,44 @@ cannot be pushed because the client needs to know them before the connection to the server can be initiated. This is a partial list of options which can currently be pushed: -.B --route, --route-gateway, --route-delay, --redirect-gateway, -.B --ip-win32, --dhcp-option, -.B --inactive, --ping, --ping-exit, --ping-restart, -.B --setenv, -.B --persist-key, --persist-tun, --echo, -.B --comp-lzo, -.B --socket-flags, -.B --sndbuf, --rcvbuf +.B \-\-route, \-\-route-gateway, \-\-route-delay, \-\-redirect-gateway, +.B \-\-ip-win32, \-\-dhcp-option, +.B \-\-inactive, \-\-ping, \-\-ping-exit, \-\-ping-restart, +.B \-\-setenv, +.B \-\-persist-key, \-\-persist-tun, \-\-echo, +.B \-\-comp-lzo, +.B \-\-socket-flags, +.B \-\-sndbuf, \-\-rcvbuf .\"********************************************************* .TP -.B --push-reset +.B \-\-push-reset Don't inherit the global push list for a specific client instance. Specify this option in a client-specific context such as with a -.B --client-config-dir +.B \-\-client-config-dir configuration file. This option will ignore -.B --push +.B \-\-push options at the global config file level. .\"********************************************************* .TP -.B --disable +.B \-\-disable Disable a particular client (based on the common name) from connecting. Don't use this option to disable a client due to key or password compromise. Use a CRL (certificate revocation list) instead (see the -.B --crl-verify +.B \-\-crl-verify option). This option must be associated with a specific client instance, which means that it must be specified either in a client instance config file using -.B --client-config-dir +.B \-\-client-config-dir or dynamically generated using a -.B --client-connect +.B \-\-client-connect script. .\"********************************************************* .TP -.B --ifconfig-pool start-IP end-IP [netmask] +.B \-\-ifconfig-pool start-IP end-IP [netmask] Set aside a pool of subnets to be dynamically allocated to connecting clients, similar to a DHCP server. For tun-style @@ -2643,7 +2644,7 @@ parameter will also be pushed to clients. .\"********************************************************* .TP -.B --ifconfig-pool-persist file [seconds] +.B \-\-ifconfig-pool-persist file [seconds] Persist/unpersist ifconfig-pool data to .B file, @@ -2658,7 +2659,7 @@ IP address assigned to them from the ifconfig-pool. Maintaining a long-term association is good for clients because it allows them to effectively use the -.B --persist-tun +.B \-\-persist-tun option. .B file @@ -2679,32 +2680,32 @@ suggestions only, based on past associations between a common name and IP address. They do not guarantee that the given common name will always receive the given IP address. If you want guaranteed assignment, use -.B --ifconfig-push +.B \-\-ifconfig-push .\"********************************************************* .TP -.B --ifconfig-pool-linear +.B \-\-ifconfig-pool-linear Modifies the -.B --ifconfig-pool +.B \-\-ifconfig-pool directive to allocate individual TUN interface addresses for clients rather than /30 subnets. NOTE: This option is incompatible with Windows clients. This option is deprecated, and should be replaced with -.B --topology p2p +.B \-\-topology p2p which is functionally equivalent. .\"********************************************************* .TP -.B --ifconfig-push local remote-netmask +.B \-\-ifconfig-push local remote-netmask Push virtual IP endpoints for client tunnel, -overriding the --ifconfig-pool dynamic allocation. +overriding the \-\-ifconfig-pool dynamic allocation. The parameters .B local and .B remote-netmask are set according to the -.B --ifconfig +.B \-\-ifconfig directive which you want to execute on the client machine to configure the remote end of the tunnel. Note that the parameters .B local @@ -2717,13 +2718,13 @@ on the server at the time of client connection. This option must be associated with a specific client instance, which means that it must be specified either in a client instance config file using -.B --client-config-dir +.B \-\-client-config-dir or dynamically generated using a -.B --client-connect +.B \-\-client-connect script. Remember also to include a -.B --route +.B \-\-route directive in the main OpenVPN config file which encloses .B local, so that the kernel will know to route it @@ -2733,23 +2734,23 @@ OpenVPN's internal client IP address selection algorithm works as follows: .B 1 --- Use -.B --client-connect script +\-\- Use +.B \-\-client-connect script generated file for static IP (first choice). .br .B 2 --- Use -.B --client-config-dir +\-\- Use +.B \-\-client-config-dir file for static IP (next choice). .br .B 3 --- Use -.B --ifconfig-pool +\-\- Use +.B \-\-ifconfig-pool allocation for dynamic IP (last choice). .br .\"********************************************************* .TP -.B --iroute network [netmask] +.B \-\-iroute network [netmask] Generate an internal route to a specific client. The .B netmask @@ -2760,36 +2761,36 @@ the server to a particular client, regardless of where the client is connecting from. Remember that you must also add the route to the system routing table as well (such as by using the -.B --route +.B \-\-route directive). The reason why two routes are needed is that the -.B --route +.B \-\-route directive routes the packet from the kernel to OpenVPN. Once in OpenVPN, the -.B --iroute +.B \-\-iroute directive routes to the specific client. This option must be specified either in a client instance config file using -.B --client-config-dir +.B \-\-client-config-dir or dynamically generated using a -.B --client-connect +.B \-\-client-connect script. The -.B --iroute +.B \-\-iroute directive also has an important interaction with -.B --push +.B \-\-push "route ...". -.B --iroute +.B \-\-iroute essentially defines a subnet which is owned by a particular client (we will call this client A). If you would like other clients to be able to reach A's subnet, you can use -.B --push +.B \-\-push "route ..." together with -.B --client-to-client +.B \-\-client-to-client to effect this. In order for all clients to see A's subnet, OpenVPN must push this route to all clients EXCEPT for A, since the subnet is already owned by A. @@ -2798,11 +2799,11 @@ not pushing a route to a client if it matches one of the client's iroutes. .\"********************************************************* .TP -.B --client-to-client +.B \-\-client-to-client Because the OpenVPN server mode handles multiple clients through a single tun or tap interface, it is effectively a router. The -.B --client-to-client +.B \-\-client-to-client flag tells OpenVPN to internally route client-to-client traffic rather than pushing all client-originating traffic to the TUN/TAP interface. @@ -2814,20 +2815,20 @@ if you want to firewall tunnel traffic using custom, per-client rules. .\"********************************************************* .TP -.B --duplicate-cn +.B \-\-duplicate-cn Allow multiple clients with the same common name to concurrently connect. In the absence of this option, OpenVPN will disconnect a client instance upon connection of a new client having the same common name. .\"********************************************************* .TP -.B --client-connect script +.B \-\-client-connect script Run .B script on client connection. The script is passed the common name and IP address of the just-authenticated client as environmental variables (see environmental variable section below). The script is also passed -the pathname of a not-yet-created temporary file as $1 +the pathname of a freshly created temporary file as $1 (i.e. the first command line argument), to be used by the script to pass dynamically generated config file directives back to OpenVPN. @@ -2836,7 +2837,7 @@ to be applied on the server when the client connects, it should write it to the file named by $1. See the -.B --client-config-dir +.B \-\-client-config-dir option below for options which can be legally used in a dynamically generated config file. @@ -2848,18 +2849,18 @@ returns a non-zero error status, it will cause the client to be disconnected. .\"********************************************************* .TP -.B --client-disconnect +.B \-\-client-disconnect Like -.B --client-connect +.B \-\-client-connect but called on client instance shutdown. Will not be called unless the -.B --client-connect +.B \-\-client-connect script and plugins (if defined) were previously called on this instance with successful (0) status returns. The exception to this rule is if the -.B --client-disconnect +.B \-\-client-disconnect script or plugins are cascaded, and at least one client-connect function succeeded, then ALL of the client-disconnect functions for scripts and plugins will be called on client instance object deletion, @@ -2868,7 +2869,7 @@ an error status. .B .\"********************************************************* .TP -.B --client-config-dir dir +.B \-\-client-config-dir dir Specify a directory .B dir for custom client config files. After @@ -2882,9 +2883,9 @@ will instead try to open and parse a default file called This file can specify a fixed IP address for a given client using -.B --ifconfig-push, +.B \-\-ifconfig-push, as well as fixed subnets owned by the client using -.B --iroute. +.B \-\-iroute. One of the useful properties of this option is that it allows client configuration files to be conveniently @@ -2893,28 +2894,28 @@ without needing to restart the server. The following options are legal in a client-specific context: -.B --push, --push-reset, --iroute, --ifconfig-push, +.B \-\-push, \-\-push-reset, \-\-iroute, \-\-ifconfig-push, and -.B --config. +.B \-\-config. .\"********************************************************* .TP -.B --ccd-exclusive +.B \-\-ccd-exclusive Require, as a condition of authentication, that a connecting client has a -.B --client-config-dir +.B \-\-client-config-dir file. .\"********************************************************* .TP -.B --tmp-dir dir +.B \-\-tmp-dir dir Specify a directory .B dir for temporary files. This directory will be used by -.B --client-connect +.B \-\-client-connect scripts to dynamically generate client-specific configuration files. .\"********************************************************* .TP -.B --hash-size r v +.B \-\-hash-size r v Set the size of the real address hash table to .B r and the virtual address table to @@ -2922,13 +2923,13 @@ and the virtual address table to By default, both tables are sized at 256 buckets. .\"********************************************************* .TP -.B --bcast-buffers n +.B \-\-bcast-buffers n Allocate .B n buffers for broadcast datagrams (default=256). .\"********************************************************* .TP -.B --tcp-queue-limit n +.B \-\-tcp-queue-limit n Maximum number of output packets queued before TCP (default=64). When OpenVPN is tunneling data from a TUN/TAP device to a @@ -2940,7 +2941,7 @@ OpenVPN will start to drop outgoing packets directed at this client. .\"********************************************************* .TP -.B --tcp-nodelay +.B \-\-tcp-nodelay This macro sets the TCP_NODELAY socket flag on the server as well as pushes it to connecting clients. The TCP_NODELAY flag disables the Nagle algorithm on TCP sockets causing @@ -2963,13 +2964,13 @@ The macro expands as follows: .fi .\"********************************************************* .TP -.B --max-clients n +.B \-\-max-clients n Limit server to a maximum of .B n concurrent clients. .\"********************************************************* .TP -.B --max-routes-per-client n +.B \-\-max-routes-per-client n Allow a maximum of .B n internal routes per client (default=256). @@ -2979,9 +2980,9 @@ server with packets appearing to come from many unique MAC addresses, forcing the server to deplete virtual memory as its internal routing table expands. This directive can be used in a -.B --client-config-dir +.B \-\-client-config-dir file or auto-generated by a -.B --client-connect +.B \-\-client-connect script to override the global value for a particular client. Note that this @@ -2989,7 +2990,7 @@ directive affects OpenVPN's internal routing table, not the kernel routing table. .\"********************************************************* .TP -.B --connect-freq n sec +.B \-\-connect-freq n sec Allow a maximum of .B n new connections per @@ -3003,12 +3004,12 @@ DoS scenario, legitimate connections might also be refused. For the best protection against DoS attacks in server mode, use -.B --proto udp +.B \-\-proto udp and -.B --tls-auth. +.B \-\-tls-auth. .\"********************************************************* .TP -.B --learn-address cmd +.B \-\-learn-address cmd Run script or shell command .B cmd to validate client virtual addresses or routes. @@ -3016,19 +3017,19 @@ to validate client virtual addresses or routes. .B cmd will be executed with 3 parameters: -.B [1] operation -- +.B [1] operation \-\- "add", "update", or "delete" based on whether or not the address is being added to, modified, or deleted from OpenVPN's internal routing table. .br -.B [2] address -- +.B [2] address \-\- The address being learned or unlearned. This can be an IPv4 address such as "198.162.10.14", an IPv4 subnet such as "198.162.10.0/24", or an ethernet MAC address (when -.B --dev tap +.B \-\-dev tap is being used) such as "00:FF:01:02:03:04". .br -.B [3] common name -- +.B [3] common name \-\- The common name on the certificate associated with the client linked to this address. Only present for "add" or "update" operations, not "delete". @@ -3048,7 +3049,7 @@ policies with regard to the client's high-level common name, rather than the low level client virtual addresses. .\"********************************************************* .TP -.B --auth-user-pass-verify script method +.B \-\-auth-user-pass-verify script method Require the client to provide a username/password (possibly in addition to a client certificate) for authentication. @@ -3079,10 +3080,10 @@ will be passed as an argument to and the file will be automatically deleted by OpenVPN after the script returns. The location of the temporary file is controlled by the -.B --tmp-dir +.B \-\-tmp-dir option, and will default to the current directory if unspecified. For security, consider setting -.B --tmp-dir +.B \-\-tmp-dir to a volatile storage medium such as .B /dev/shm (if available) to prevent the username/password file from touching the hard drive. @@ -3114,7 +3115,7 @@ For a sample script that performs PAM authentication, see in the OpenVPN source distribution. .\"********************************************************* .TP -.B --opt-verify +.B \-\-opt-verify Clients that connect with options that are incompatible with those of the server will be disconnected. @@ -3124,16 +3125,16 @@ comp-lzo, fragment, keydir, cipher, auth, keysize, secret, no-replay, no-iv, tls-auth, key-method, tls-server, and tls-client. This option requires that -.B --disable-occ +.B \-\-disable-occ NOT be used. .\"********************************************************* .TP -.B --auth-user-pass-optional +.B \-\-auth-user-pass-optional Allow connections by clients that do not specify a username/password. Normally, when -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify or -.B --management-client-auth +.B \-\-management-client-auth is specified (or an authentication plugin module), the OpenVPN server daemon will require connecting clients to specify a username and password. This option makes the submission of a username/password @@ -3146,35 +3147,35 @@ to empty strings (""). The authentication module/script MUST have logic to detect this condition and respond accordingly. .\"********************************************************* .TP -.B --client-cert-not-required +.B \-\-client-cert-not-required Don't require client certificate, client will authenticate using username/password only. Be aware that using this directive is less secure than requiring certificates from all clients. If you use this directive, the entire responsibility of authentication will rest on your -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify script, so keep in mind that bugs in your script could potentially compromise the security of your VPN. If you don't use this directive, but you also specify an -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify script, then OpenVPN will perform double authentication. The client certificate verification AND the -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify script will need to succeed in order for a client to be authenticated and accepted onto the VPN. .\"********************************************************* .TP -.B --username-as-common-name +.B \-\-username-as-common-name For -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify authentication, use the authenticated username as the common name, rather than the common name from the client cert. .\"********************************************************* .TP -.B --no-name-remapping +.B \-\-no-name-remapping Allow Common Name, X509 Subject, and username strings to include any printable character including space, but excluding control characters such as tab, newline, and carriage-return. @@ -3195,7 +3196,7 @@ disable the remapping feature. Don't use this option unless you know what you are doing! .\"********************************************************* .TP -.B --port-share host port +.B \-\-port-share host port When run in TCP server mode, share the OpenVPN port with another application, such as an HTTPS server. If OpenVPN senses a connection to its port which is using a non-OpenVPN @@ -3210,13 +3211,13 @@ Not implemented on Windows. .SS Client Mode Use client mode when connecting to an OpenVPN server which has -.B --server, --server-bridge, +.B \-\-server, \-\-server-bridge, or -.B --mode server +.B \-\-mode server in it's configuration. .\"********************************************************* .TP -.B --client +.B \-\-client A helper directive designed to simplify the configuration of OpenVPN's client mode. This directive is equivalent to: @@ -3230,33 +3231,33 @@ of OpenVPN's client mode. This directive is equivalent to: .fi .\"********************************************************* .TP -.B --pull +.B \-\-pull This option must be used on a client which is connecting to a multi-client server. It indicates to OpenVPN that it should accept options pushed by the server, provided they are part of the legal set of pushable options (note that the -.B --pull +.B \-\-pull option is implied by -.B --client +.B \-\-client ). In particular, -.B --pull +.B \-\-pull allows the server to push routes to the client, so you should not use -.B --pull +.B \-\-pull or -.B --client +.B \-\-client in situations where you don't trust the server to have control over the client's routing table. .\"********************************************************* .TP -.B --auth-user-pass [up] +.B \-\-auth-user-pass [up] Authenticate with server using username/password. .B up is a file containing username/password on 2 lines (Note: OpenVPN will only read passwords from a file if it has been built -with the --enable-password-save configure option, or on Windows +with the \-\-enable-password-save configure option, or on Windows by defining ENABLE_PASSWORD_SAVE in config-win32.h). If @@ -3265,12 +3266,12 @@ is omitted, username/password will be prompted from the console. The server configuration must specify an -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify script to verify the username/password provided by the client. .\"********************************************************* .TP -.B --auth-retry type +.B \-\-auth-retry type Controls how OpenVPN responds to username/password verification errors such as the client-side response to an AUTH_FAILED message from the server or verification failure of the private key password. @@ -3281,40 +3282,40 @@ of error. An AUTH_FAILED message is generated by the server if the client fails -.B --auth-user-pass +.B \-\-auth-user-pass authentication, or if the server-side -.B --client-connect +.B \-\-client-connect script returns an error status when the client tries to connect. .B type can be one of: -.B none -- +.B none \-\- Client will exit with a fatal error (this is the default). .br -.B nointeract -- +.B nointeract \-\- Client will retry the connection without requerying for an -.B --auth-user-pass +.B \-\-auth-user-pass username/password. Use this option for unattended clients. .br -.B interact -- +.B interact \-\- Client will requery for an -.B --auth-user-pass +.B \-\-auth-user-pass username/password and/or private key password before attempting a reconnection. Note that while this option cannot be pushed, it can be controlled from the management interface. .\"********************************************************* .TP -.B --server-poll-timeout n +.B \-\-server-poll-timeout n when polling possible remote servers to connect to in a round-robin fashion, spend no more than .B n seconds waiting for a response before trying the next server. .\"********************************************************* .TP -.B --explicit-exit-notify [n] +.B \-\-explicit-exit-notify [n] In UDP client mode or point-to-point mode, send server/peer an exit notification if tunnel is restarted or OpenVPN process is exited. In client mode, on exit/restart, this @@ -3329,12 +3330,12 @@ These options are meaningful for both Static & TLS-negotiated key modes (must be compatible between peers). .\"********************************************************* .TP -.B --secret file [direction] +.B \-\-secret file [direction] Enable Static Key encryption mode (non-TLS). Use pre-shared secret .B file which was generated with -.B --genkey. +.B \-\-genkey. The optional .B direction @@ -3365,7 +3366,7 @@ supports the .B direction parameter, will also support 2048 bit key file generation using the -.B --genkey +.B \-\-genkey option. Static key encryption mode has certain advantages, @@ -3395,7 +3396,7 @@ would see nothing but random-looking data. .\"********************************************************* .TP -.B --auth alg +.B \-\-auth alg Authenticate packets with HMAC using message digest algorithm .B alg. @@ -3410,7 +3411,7 @@ OpenVPN's usage of HMAC is to first encrypt a packet, then HMAC the resulting ci In static-key encryption mode, the HMAC key is included in the key file generated by -.B --genkey. +.B \-\-genkey. In TLS mode, the HMAC key is dynamically generated and shared between peers via the TLS control channel. If OpenVPN receives a packet with a bad HMAC it will drop the packet. @@ -3423,7 +3424,7 @@ For more information on HMAC see .I http://www.cs.ucsd.edu/users/mihir/papers/hmac.html .\"********************************************************* .TP -.B --cipher alg +.B \-\-cipher alg Encrypt packets with cipher algorithm .B alg. The default is @@ -3438,7 +3439,7 @@ For more information on blowfish, see To see other ciphers that are available with OpenVPN, use the -.B --show-ciphers +.B \-\-show-ciphers option. OpenVPN supports the CBC, CFB, and OFB cipher modes, @@ -3450,10 +3451,10 @@ Set to disable encryption. .\"********************************************************* .TP -.B --keysize n +.B \-\-keysize n Size of cipher key in bits (optional). If unspecified, defaults to cipher-specific default. The -.B --show-ciphers +.B \-\-show-ciphers option (see below) shows all available OpenSSL ciphers, their default key sizes, and whether the key size can be changed. Use care in changing a cipher's default @@ -3463,7 +3464,7 @@ larger key may offer no real guarantee of greater security, or may even reduce security. .\"********************************************************* .TP -.B --prng alg [nsl] +.B \-\-prng alg [nsl] (Advanced) For PRNG (Pseudo-random number generator), use digest algorithm .B alg @@ -3478,19 +3479,19 @@ to disable the PRNG and use the OpenSSL RAND_bytes function instead for all of OpenVPN's pseudo-random number needs. .\"********************************************************* .TP -.B --engine [engine-name] +.B \-\-engine [engine-name] Enable OpenSSL hardware-based crypto engine functionality. If .B engine-name is specified, use a specific crypto engine. Use the -.B --show-engines +.B \-\-show-engines standalone option to list the crypto engines which are supported by OpenSSL. .\"********************************************************* .TP -.B --no-replay +.B \-\-no-replay (Advanced) Disable OpenVPN's protection against replay attacks. Don't use this option unless you are prepared to make a tradeoff of greater efficiency in exchange for less @@ -3534,7 +3535,7 @@ algorithm used by IPSec. .\"********************************************************* .TP -.B --replay-window n [t] +.B \-\-replay-window n [t] Use a replay protection sliding-window of size .B n and a time window of @@ -3549,9 +3550,9 @@ is 15 seconds. This option is only relevant in UDP mode, i.e. when either -.B --proto udp +.B \-\-proto udp is specifed, or no -.B --proto +.B \-\-proto option is specified. When OpenVPN tunnels IP packets over UDP, there is the possibility that @@ -3563,7 +3564,7 @@ the TCP/IP protocol stack, provided they satisfy several constraints. .B (a) The packet cannot be a replay (unless -.B --no-replay +.B \-\-no-replay is specified, which disables replay protection altogether). .B (b) @@ -3585,7 +3586,7 @@ a larger value for Satellite links in particular often require this. If you run OpenVPN at -.B --verb 4, +.B \-\-verb 4, you will see the message "Replay-window backtrack occurred [x]" every time the maximum sequence number backtrack seen thus far increases. This can be used to calibrate @@ -3621,7 +3622,7 @@ parameters of what is to be expected from the physical IP layer. The problem is easily fixed by simply using TCP as the VPN transport layer. .\"********************************************************* .TP -.B --mute-replay-warnings +.B \-\-mute-replay-warnings Silence the output of replay warnings, which are a common false alarm on WiFi networks. This option preserves the security of the replay protection code without @@ -3629,7 +3630,7 @@ the verbosity associated with warnings about duplicate packets. .\"********************************************************* .TP -.B --replay-persist file +.B \-\-replay-persist file Persist replay-protection state across sessions using .B file to save and reload the state. @@ -3637,7 +3638,7 @@ to save and reload the state. This option will strengthen protection against replay attacks, especially when you are using OpenVPN in a dynamic context (such as with -.B --inetd) +.B \-\-inetd) when OpenVPN sessions are frequently started and stopped. This option will keep a disk copy of the current replay protection @@ -3648,12 +3649,12 @@ which were already received by the prior session. This option only makes sense when replay protection is enabled (the default) and you are using either -.B --secret +.B \-\-secret (shared-secret key mode) or TLS mode with -.B --tls-auth. +.B \-\-tls-auth. .\"********************************************************* .TP -.B --no-iv +.B \-\-no-iv (Advanced) Disable OpenVPN's use of IV (cipher initialization vector). Don't use this option unless you are prepared to make a tradeoff of greater efficiency in exchange for less @@ -3674,24 +3675,24 @@ space-saving optimization that uses the unique identifier for datagram replay protection as the IV. .\"********************************************************* .TP -.B --test-crypto +.B \-\-test-crypto Do a self-test of OpenVPN's crypto options by encrypting and decrypting test packets using the data channel encryption options specified above. This option does not require a peer to function, and therefore can be specified without -.B --dev +.B \-\-dev or -.B --remote. +.B \-\-remote. The typical usage of -.B --test-crypto +.B \-\-test-crypto would be something like this: -.B openvpn --test-crypto --secret key +.B openvpn \-\-test-crypto \-\-secret key or -.B openvpn --test-crypto --secret key --verb 9 +.B openvpn \-\-test-crypto \-\-secret key \-\-verb 9 This option is very useful to test OpenVPN after it has been ported to a new platform, or to isolate problems in the compiler, OpenSSL @@ -3715,17 +3716,17 @@ including certificate-based authentication and Diffie Hellman forward secrecy. To use TLS mode, each peer that runs OpenVPN should have its own local certificate/key pair ( -.B --cert +.B \-\-cert and -.B --key +.B \-\-key ), signed by the root certificate which is specified in -.B --ca. +.B \-\-ca. When two OpenVPN peers connect, each presents its local certificate to the other. Each peer will then check that its partner peer presented a certificate which was signed by the master root certificate as specified in -.B --ca. +.B \-\-ca. If that check on both peers succeeds, then the TLS negotiation will succeed, both OpenVPN @@ -3742,18 +3743,18 @@ The easy-rsa package is also rendered in web form here: .I http://openvpn.net/easyrsa.html .\"********************************************************* .TP -.B --tls-server +.B \-\-tls-server Enable TLS and assume server role during TLS handshake. Note that OpenVPN is designed as a peer-to-peer application. The designation of client or server is only for the purpose of negotiating the TLS control channel. .\"********************************************************* .TP -.B --tls-client +.B \-\-tls-client Enable TLS and assume client role during TLS handshake. .\"********************************************************* .TP -.B --ca file +.B \-\-ca file Certificate authority (CA) file in .pem format, also referred to as the .I root certificate. This file can have multiple @@ -3775,10 +3776,10 @@ production environment, since by virtue of the fact that they are distributed with OpenVPN, they are totally insecure. .\"********************************************************* .TP -.B --dh file +.B \-\-dh file File containing Diffie Hellman parameters in .pem format (required for -.B --tls-server +.B \-\-tls-server only). Use .B openssl dhparam -out dh1024.pem 1024 @@ -3788,15 +3789,15 @@ included with the OpenVPN distribution. Diffie Hellman parameters may be considered public. .\"********************************************************* .TP -.B --cert file -Local peer's signed certificate in .pem format -- must be signed +.B \-\-cert file +Local peer's signed certificate in .pem format \-\- must be signed by a certificate authority whose certificate is in -.B --ca file. +.B \-\-ca file. Each peer in an OpenVPN link running in TLS mode should have its own certificate and private key file. In addition, each certificate should have been signed by the key of a certificate authority whose public key resides in the -.B --ca +.B \-\-ca certificate authority file. You can easily make your own certificate authority (see above) or pay money to use a commercial service such as thawte.com (in which case you will be @@ -3821,7 +3822,7 @@ Note that the command reads the location of the certificate authority key from its configuration file such as .B /usr/share/ssl/openssl.cnf --- note also +\-\- note also that for certificate authority functions, you must set up the files .B index.txt (may be empty) and @@ -3832,90 +3833,90 @@ that for certificate authority functions, you must set up the files ). .\"********************************************************* .TP -.B --key file +.B \-\-key file Local peer's private key in .pem format. Use the private key which was generated when you built your peer's certificate (see .B -cert file above). .\"********************************************************* .TP -.B --pkcs12 file +.B \-\-pkcs12 file Specify a PKCS #12 file containing local private key, local certificate, and root CA certificate. This option can be used instead of -.B --ca, --cert, +.B \-\-ca, \-\-cert, and -.B --key. +.B \-\-key. .\"********************************************************* .TP -.B --pkcs11-cert-private [0|1]... +.B \-\-pkcs11-cert-private [0|1]... Set if access to certificate object should be performed after login. Every provider has its own setting. .\"********************************************************* .TP -.B --pkcs11-id name +.B \-\-pkcs11-id name Specify the serialized certificate id to be used. The id can be gotten by the standalone -.B --show-pkcs11-ids +.B \-\-show-pkcs11-ids option. .\"********************************************************* .TP -.B --pkcs11-id-management +.B \-\-pkcs11-id-management Acquire PKCS#11 id from management interface. In this case a NEED-STR 'pkcs11-id-request' real-time message will be triggered, application may use pkcs11-id-count command to retrieve available number of certificates, and pkcs11-id-get command to retrieve certificate id and certificate body. .\"********************************************************* .TP -.B --pkcs11-pin-cache seconds +.B \-\-pkcs11-pin-cache seconds Specify how many seconds the PIN can be cached, the default is until the token is removed. .\"********************************************************* .TP -.B --pkcs11-protected-authentication [0|1]... +.B \-\-pkcs11-protected-authentication [0|1]... Use PKCS#11 protected authentication path, useful for biometric and external keypad devices. Every provider has its own setting. .\"********************************************************* .TP -.B --pkcs11-providers provider... +.B \-\-pkcs11-providers provider... Specify a RSA Security Inc. PKCS #11 Cryptographic Token Interface (Cryptoki) providers to load. This option can be used instead of -.B --cert, --key, +.B \-\-cert, \-\-key, and -.B --pkcs12. +.B \-\-pkcs12. .\"********************************************************* .TP -.B --pkcs11-private-mode mode... +.B \-\-pkcs11-private-mode mode... Specify which method to use in order to perform private key operations. A different mode can be specified for each provider. Mode is encoded as hex number, and can be a mask one of the following: .B 0 -(default) -- Try to determind automatically. +(default) \-\- Try to determind automatically. .br .B 1 --- Use sign. +\-\- Use sign. .br .B 2 --- Use sign recover. +\-\- Use sign recover. .br .B 4 --- Use decrypt. +\-\- Use decrypt. .br .B 8 --- Use unwrap. +\-\- Use unwrap. .br .\"********************************************************* .TP -.B --cryptoapicert select-string +.B \-\-cryptoapicert select-string Load the certificate and private key from the Windows Certificate System Store (Windows Only). Use this option instead of -.B --cert +.B \-\-cert and -.B --key. +.B \-\-key. This makes it possible to use any smart card, supported by Windows, but also any @@ -3941,7 +3942,7 @@ Certificate Store GUI. .\"********************************************************* .TP -.B --key-method m +.B \-\-key-method m Use data channel key negotiation method .B m. The key method must match on both sides of the connection. @@ -3969,16 +3970,16 @@ of keying occur: of the connection producing certificates and verifying the certificate (or other authentication info provided) of the other side. The -.B --key-method +.B \-\-key-method parameter has no effect on this process. (2) After the TLS connection is established, the tunnel session keys are separately negotiated over the existing secure TLS channel. Here, -.B --key-method +.B \-\-key-method determines the derivation of the tunnel session keys. .\"********************************************************* .TP -.B --tls-cipher l +.B \-\-tls-cipher l A list .B l of allowable TLS ciphers delimited by a colon (":"). @@ -3988,11 +3989,11 @@ version rollback attack where a man-in-the-middle attacker tries to force two peers to negotiate to the lowest level of security they both support. Use -.B --show-tls +.B \-\-show-tls to see a list of supported TLS ciphers. .\"********************************************************* .TP -.B --tls-timeout n +.B \-\-tls-timeout n Packet retransmit timeout on TLS control channel if no acknowledgment from remote within .B n @@ -4009,7 +4010,7 @@ the higher level network protocols running on top of the tunnel such as TCP expect this role to be left to them. .\"********************************************************* .TP -.B --reneg-bytes n +.B \-\-reneg-bytes n Renegotiate data channel key after .B n bytes sent or received (disabled by default). @@ -4019,13 +4020,13 @@ a number of seconds. A key renegotiation will be forced if any of these three criteria are met by either peer. .\"********************************************************* .TP -.B --reneg-pkts n +.B \-\-reneg-pkts n Renegotiate data channel key after .B n packets sent and received (disabled by default). .\"********************************************************* .TP -.B --reneg-sec n +.B \-\-reneg-sec n Renegotiate data channel key after .B n seconds (default=3600). @@ -4036,16 +4037,16 @@ cause the end user to be challenged to reauthorize once per hour. Also, keep in mind that this option can be used on both the client and server, and whichever uses the lower value will be the one to trigger the renegotiation. A common mistake is to set -.B --reneg-sec +.B \-\-reneg-sec to a higher value on either the client or server, while the other side of the connection is still using the default value of 3600 seconds, meaning that the renegotiation will -still occur once per 3600 seconds. The solution is to increase --reneg-sec on both the +still occur once per 3600 seconds. The solution is to increase \-\-reneg-sec on both the client and server, or set it to 0 on one side of the connection (to disable), and to your chosen value on the other side. .\"********************************************************* .TP -.B --hand-window n -Handshake Window -- the TLS-based key exchange must finalize within +.B \-\-hand-window n +Handshake Window \-\- the TLS-based key exchange must finalize within .B n seconds of handshake initiation by any peer (default = 60 seconds). @@ -4053,47 +4054,47 @@ If the handshake fails we will attempt to reset our connection with our peer and try again. Even in the event of handshake failure we will still use our expiring key for up to -.B --tran-window +.B \-\-tran-window seconds to maintain continuity of transmission of tunnel data. .\"********************************************************* .TP -.B --tran-window n -Transition window -- our old key can live this many seconds +.B \-\-tran-window n +Transition window \-\- our old key can live this many seconds after a new a key renegotiation begins (default = 3600 seconds). This feature allows for a graceful transition from old to new key, and removes the key renegotiation sequence from the critical path of tunnel data forwarding. .\"********************************************************* .TP -.B --single-session +.B \-\-single-session After initially connecting to a remote peer, disallow any new connections. Using this option means that a remote peer cannot connect, disconnect, and then reconnect. If the daemon is reset by a signal or -.B --ping-restart, +.B \-\-ping-restart, it will allow one new connection. -.B --single-session +.B \-\-single-session can be used with -.B --ping-exit +.B \-\-ping-exit or -.B --inactive +.B \-\-inactive to create a single dynamic session that will exit when finished. .\"********************************************************* .TP -.B --tls-exit +.B \-\-tls-exit Exit on TLS negotiation failure. .\"********************************************************* .TP -.B --tls-auth file [direction] +.B \-\-tls-auth file [direction] Add an additional layer of HMAC authentication on top of the TLS control channel to protect against DoS attacks. In a nutshell, -.B --tls-auth +.B \-\-tls-auth enables a kind of "HMAC firewall" on OpenVPN's TCP/UDP port, where TLS control channel packets bearing an incorrect HMAC signature can be dropped immediately without @@ -4104,7 +4105,7 @@ response. .B (1) An OpenVPN static key file generated by -.B --genkey +.B \-\-genkey (required if .B direction parameter is used). @@ -4122,19 +4123,19 @@ OpenVPN will first try format (1), and if the file fails to parse as a static key file, format (2) will be used. See the -.B --secret +.B \-\-secret option for more information on the optional .B direction parameter. -.B --tls-auth +.B \-\-tls-auth is recommended when you are running OpenVPN in a mode where it is listening for packets from any IP address, such as when -.B --remote +.B \-\-remote is not specified, or -.B --remote +.B \-\-remote is specified with -.B --float. +.B \-\-float. The rationale for this feature is as follows. TLS requires a multi-packet exchange @@ -4161,7 +4162,7 @@ An important rule of thumb in reducing vulnerability to DoS attacks is to minimize the amount of resources a potential, but as yet unauthenticated, client is able to consume. -.B --tls-auth +.B \-\-tls-auth does this by signing every TLS control channel packet with an HMAC signature, including packets which are sent before the TLS level has had a chance to authenticate the peer. @@ -4169,20 +4170,20 @@ The result is that packets without the correct signature can be dropped immediately upon reception, before they have a chance to consume additional system resources such as by initiating a TLS handshake. -.B --tls-auth +.B \-\-tls-auth can be strengthened by adding the -.B --replay-persist +.B \-\-replay-persist option which will keep OpenVPN's replay protection state in a file so that it is not lost across restarts. It should be emphasized that this feature is optional and that the passphrase/key file used with -.B --tls-auth +.B \-\-tls-auth gives a peer nothing more than the power to initiate a TLS handshake. It is not used to encrypt or authenticate any tunnel data. .\"********************************************************* .TP -.B --askpass [file] +.B \-\-askpass [file] Get certificate password from console or .B file before we daemonize. @@ -4191,7 +4192,7 @@ For the extremely security conscious, it is possible to protect your private key with a password. Of course this means that every time the OpenVPN daemon is started you must be there to type the password. The -.B --askpass +.B \-\-askpass option allows you to start OpenVPN from the command line. It will query you for a password before it daemonizes. To protect a private key with a password you should omit the @@ -4208,15 +4209,15 @@ Keep in mind that storing your password in a file to a certain extent invalidates the extra security provided by using an encrypted key (Note: OpenVPN will only read passwords from a file if it has been built -with the --enable-password-save configure option, or on Windows +with the \-\-enable-password-save configure option, or on Windows by defining ENABLE_PASSWORD_SAVE in config-win32.h). .\"********************************************************* .TP -.B --auth-nocache +.B \-\-auth-nocache Don't cache -.B --askpass +.B \-\-askpass or -.B --auth-user-pass +.B \-\-auth-user-pass username/passwords in virtual memory. If specified, this directive will cause OpenVPN to immediately @@ -4226,19 +4227,19 @@ from stdin, which may be multiple times during the duration of an OpenVPN session. This directive does not affect the -.B --http-proxy +.B \-\-http-proxy username/password. It is always cached. .\"********************************************************* .TP -.B --tls-verify cmd +.B \-\-tls-verify cmd Execute shell command .B cmd to verify the X509 name of a pending TLS connection that has otherwise passed all other tests of certification (except for revocation via -.B --crl-verify +.B \-\-crl-verify directive; the revocation test occurs after the -.B --tls-verify +.B \-\-tls-verify test). .B cmd @@ -4271,7 +4272,7 @@ to to build a command line which will be passed to the script. .\"********************************************************* .TP -.B --tls-remote name +.B \-\-tls-remote name Accept connections only from a host with X509 name or common name equal to .B name. @@ -4281,24 +4282,24 @@ of verification. Name can also be a common name prefix, for example if you want a client to only accept connections to "Server-1", "Server-2", etc., you can simply use -.B --tls-remote Server +.B \-\-tls-remote Server Using a common name prefix is a useful alternative to managing a CRL (Certificate Revocation List) on the client, since it allows the client to refuse all certificates except for those associated with designated servers. -.B --tls-remote +.B \-\-tls-remote is a useful replacement for the -.B --tls-verify +.B \-\-tls-verify option to verify the remote host, because -.B --tls-remote +.B \-\-tls-remote works in a -.B --chroot +.B \-\-chroot environment too. .\"********************************************************* .TP -.B --ns-cert-type client|server +.B \-\-ns-cert-type client|server Require that peer certificate was signed with an explicit .B nsCertType designation of "client" or "server". @@ -4313,19 +4314,19 @@ field set to "server". If the server certificate's nsCertType field is set to "server", then the clients can verify this with -.B --ns-cert-type server. +.B \-\-ns-cert-type server. This is an important security precaution to protect against a man-in-the-middle attack where an authorized client attempts to connect to another client by impersonating the server. The attack is easily prevented by having clients verify the server certificate using any one of -.B --ns-cert-type, --tls-remote, +.B \-\-ns-cert-type, \-\-tls-remote, or -.B --tls-verify. +.B \-\-tls-verify. .\"********************************************************* .TP -.B --remote-cert-ku v... +.B \-\-remote-cert-ku v... Require that peer certificate was signed with an explicit .B key usage. @@ -4336,7 +4337,7 @@ The key usage should be encoded in hex, more than one key usage can be specified. .\"********************************************************* .TP -.B --remote-cert-eku oid +.B \-\-remote-cert-eku oid Require that peer certificate was signed with an explicit .B extended key usage. @@ -4347,7 +4348,7 @@ The extended key usage should be encoded in oid notation, or OpenSSL symbolic representation. .\"********************************************************* .TP -.B --remote-cert-tls client|server +.B \-\-remote-cert-tls client|server Require that peer certificate was signed with an explicit .B key usage and @@ -4358,18 +4359,18 @@ This is a useful security option for clients, to ensure that the host they connect to is a designated server. The -.B --remote-cert-tls client +.B \-\-remote-cert-tls client option is equivalent to .B ---remote-cert-ku 80 08 88 --remote-cert-eku "TLS Web Client Authentication" +\-\-remote-cert-ku 80 08 88 \-\-remote-cert-eku "TLS Web Client Authentication" The key usage is digitalSignature and/or keyAgreement. The -.B --remote-cert-tls server +.B \-\-remote-cert-tls server option is equivalent to .B ---remote-cert-ku a0 88 --remote-cert-eku "TLS Web Server Authentication" +\-\-remote-cert-ku a0 88 \-\-remote-cert-eku "TLS Web Server Authentication" The key usage is digitalSignature and ( keyEncipherment or keyAgreement ). @@ -4378,12 +4379,12 @@ a man-in-the-middle attack where an authorized client attempts to connect to another client by impersonating the server. The attack is easily prevented by having clients verify the server certificate using any one of -.B --remote-cert-tls, --tls-remote, +.B \-\-remote-cert-tls, \-\-tls-remote, or -.B --tls-verify. +.B \-\-tls-verify. .\"********************************************************* .TP -.B --crl-verify crl +.B \-\-crl-verify crl Check peer certificate against the file .B crl in PEM format. @@ -4403,28 +4404,28 @@ if the root certificate key itself was compromised. .SS SSL Library information: .\"********************************************************* .TP -.B --show-ciphers +.B \-\-show-ciphers (Standalone) Show all cipher algorithms to use with the -.B --cipher +.B \-\-cipher option. .\"********************************************************* .TP -.B --show-digests +.B \-\-show-digests (Standalone) Show all message digest algorithms to use with the -.B --auth +.B \-\-auth option. .\"********************************************************* .TP -.B --show-tls +.B \-\-show-tls (Standalone) Show all TLS ciphers (TLS used only as a control channel). The TLS ciphers will be sorted from highest preference (most secure) to lowest. .\"********************************************************* .TP -.B --show-engines +.B \-\-show-engines (Standalone) Show currently available hardware-based crypto acceleration engines supported by the OpenSSL library. @@ -4433,18 +4434,18 @@ engines supported by the OpenSSL library. Used only for non-TLS static key encryption mode. .\"********************************************************* .TP -.B --genkey +.B \-\-genkey (Standalone) Generate a random key to be used as a shared secret, for use with the -.B --secret +.B \-\-secret option. This file must be shared with the peer over a pre-existing secure channel such as .BR scp (1) . .\"********************************************************* .TP -.B --secret file +.B \-\-secret file Write key to .B file. .\"********************************************************* @@ -4453,7 +4454,7 @@ Available with linux 2.4.7+. These options comprise a standalone mode of OpenVPN which can be used to create and delete persistent tunnels. .\"********************************************************* .TP -.B --mktun +.B \-\-mktun (Standalone) Create a persistent tunnel on platforms which support them such as Linux. Normally TUN/TAP tunnels exist only for @@ -4464,9 +4465,9 @@ only when they are deleted or the machine is rebooted. One of the advantages of persistent tunnels is that they eliminate the need for separate -.B --up +.B \-\-up and -.B --down +.B \-\-down scripts to run the appropriate .BR ifconfig (8) and @@ -4478,40 +4479,40 @@ Another advantage is that open connections through the TUN/TAP-based tunnel will not be reset if the OpenVPN peer restarts. This can be useful to provide uninterrupted connectivity through the tunnel in the event of a DHCP reset of the peer's public IP address (see the -.B --ipchange +.B \-\-ipchange option above). One disadvantage of persistent tunnels is that it is harder to automatically configure their MTU value (see -.B --link-mtu +.B \-\-link-mtu and -.B --tun-mtu +.B \-\-tun-mtu above). On some platforms such as Windows, TAP-Win32 tunnels are persistent by default. .\"********************************************************* .TP -.B --rmtun +.B \-\-rmtun (Standalone) Remove a persistent tunnel. .\"********************************************************* .TP -.B --dev tunX | tapX +.B \-\-dev tunX | tapX TUN/TAP device .\"********************************************************* .TP -.B --user user +.B \-\-user user Optional user to be owner of this tunnel. .\"********************************************************* .TP -.B --group group +.B \-\-group group Optional group to be owner of this tunnel. .\"********************************************************* .SS Windows-Specific Options: .\"********************************************************* .TP -.B --win-sys path|'env' +.B \-\-win-sys path|'env' Set the Windows system directory pathname to use when looking for system executables such as .B route.exe @@ -4527,23 +4528,23 @@ indicates that the pathname should be read from the environmental variable. .\"********************************************************* .TP -.B --ip-win32 method +.B \-\-ip-win32 method When using -.B --ifconfig +.B \-\-ifconfig on Windows, set the TAP-Win32 adapter IP address and netmask using .B method. Don't use this option unless you are also using -.B --ifconfig. +.B \-\-ifconfig. -.B manual -- +.B manual \-\- Don't set the IP address or netmask automatically. Instead output a message to the console telling the user to configure the adapter manually and indicating the IP/netmask which OpenVPN expects the adapter to be set to. -.B dynamic [offset] [lease-time] -- +.B dynamic [offset] [lease-time] \-\- Automatically set the IP address and netmask by replying to DHCP query messages generated by the kernel. This mode is probably the "cleanest" solution @@ -4553,13 +4554,13 @@ this mode: (1) The TCP/IP properties for the TAP-Win32 adapter must be set to "Obtain an IP address automatically," and (2) OpenVPN needs to claim an IP address in the subnet for use as the virtual DHCP server address. By default in -.B --dev tap +.B \-\-dev tap mode, OpenVPN will take the normally unused first address in the subnet. For example, if your subnet is 192.168.4.0 netmask 255.255.255.0, then OpenVPN will take the IP address 192.168.4.0 to use as the virtual DHCP server address. In -.B --dev tun +.B \-\-dev tun mode, OpenVPN will cause the DHCP server to masquerade as if it were coming from the remote endpoint. The optional offset parameter is an integer which is > -256 and < 256 and which defaults to 0. @@ -4581,13 +4582,13 @@ because it prevents routes involving the TAP-Win32 adapter from being lost when the system goes to sleep. The default lease time is one year. -.B netsh -- +.B netsh \-\- Automatically set the IP address and netmask using the Windows command-line "netsh" command. This method appears to work correctly on Windows XP but not Windows 2000. -.B ipapi -- +.B ipapi \-\- Automatically set the IP address and netmask using the Windows IP Helper API. This approach does not have ideal semantics, though testing has indicated @@ -4596,7 +4597,7 @@ it is best to leave the TCP/IP properties for the TAP-Win32 adapter in their default state, i.e. "Obtain an IP address automatically." -.B adaptive -- +.B adaptive \-\- (Default) Try .B dynamic method initially and fail over to @@ -4626,55 +4627,55 @@ mode to restore the TAP-Win32 adapter TCP/IP properties to a DHCP configuration. .\"********************************************************* .TP -.B --route-method m +.B \-\-route-method m Which method .B m to use for adding routes on Windows? .B adaptive -(default) -- Try IP helper API first. If that fails, fall +(default) \-\- Try IP helper API first. If that fails, fall back to the route.exe shell command. .br .B ipapi --- Use IP helper API. +\-\- Use IP helper API. .br .B exe --- Call the route.exe shell command. +\-\- Call the route.exe shell command. .\"********************************************************* .TP -.B --dhcp-option type [parm] +.B \-\-dhcp-option type [parm] Set extended TAP-Win32 TCP/IP properties, must be used with -.B --ip-win32 dynamic +.B \-\-ip-win32 dynamic or -.B --ip-win32 adaptive. +.B \-\-ip-win32 adaptive. This option can be used to set additional TCP/IP properties on the TAP-Win32 adapter, and is particularly useful for configuring an OpenVPN client to access a Samba server across the VPN. -.B DOMAIN name -- +.B DOMAIN name \-\- Set Connection-specific DNS Suffix. -.B DNS addr -- +.B DNS addr \-\- Set primary domain name server address. Repeat this option to set secondary DNS server addresses. -.B WINS addr -- +.B WINS addr \-\- Set primary WINS server address (NetBIOS over TCP/IP Name Server). Repeat this option to set secondary WINS server addresses. -.B NBDD addr -- +.B NBDD addr \-\- Set primary NBDD server address (NetBIOS over TCP/IP Datagram Distribution Server) Repeat this option to set secondary NBDD server addresses. -.B NTP addr -- +.B NTP addr \-\- Set primary NTP server address (Network Time Protocol). Repeat this option to set secondary NTP server addresses. -.B NBT type -- +.B NBT type \-\- Set NetBIOS over TCP/IP Node type. Possible options: .B 1 = b-node (broadcasts), @@ -4687,7 +4688,7 @@ then query name server), and .B 8 = h-node (query name server, then broadcast). -.B NBS scope-id -- +.B NBS scope-id \-\- Set NetBIOS over TCP/IP Scope. A NetBIOS Scope ID provides an extended naming service for the NetBIOS over TCP/IP (Known as NBT) module. The primary purpose of a NetBIOS scope ID is to isolate NetBIOS traffic on @@ -4699,19 +4700,19 @@ computers to use the same computer name, as they have different scope IDs. The Scope ID becomes a part of the NetBIOS name, making the name unique. (This description of NetBIOS scopes courtesy of NeonSurge@abyss.com) -.B DISABLE-NBT -- +.B DISABLE-NBT \-\- Disable Netbios-over-TCP/IP. Note that if -.B --dhcp-option +.B \-\-dhcp-option is pushed via -.B --push +.B \-\-push to a non-windows client, the option will be saved in the client's environment before the up script is called, under the name "foreign_option_{n}". .\"********************************************************* .TP -.B --tap-sleep n +.B \-\-tap-sleep n Cause OpenVPN to sleep for .B n seconds immediately after the TAP-Win32 adapter state @@ -4719,21 +4720,21 @@ is set to "connected". This option is intended to be used to troubleshoot problems with the -.B --ifconfig +.B \-\-ifconfig and -.B --ip-win32 +.B \-\-ip-win32 options, and is used to give the TAP-Win32 adapter time to come up before Windows IP Helper API operations are applied to it. .\"********************************************************* .TP -.B --show-net-up +.B \-\-show-net-up Output OpenVPN's view of the system routing table and network adapter list to the syslog or log file after the TUN/TAP adapter has been brought up and any routes have been added. .\"********************************************************* .TP -.B --dhcp-renew +.B \-\-dhcp-renew Ask Windows to renew the TAP adapter lease on startup. This option is normally unnecessary, as Windows automatically triggers a DHCP renegotiation on the TAP adapter when it @@ -4742,27 +4743,27 @@ Media Status property to "Always Connected", you may need this flag. .\"********************************************************* .TP -.B --dhcp-release +.B \-\-dhcp-release Ask Windows to release the TAP adapter lease on shutdown. This option has the same caveats as -.B --dhcp-renew +.B \-\-dhcp-renew above. .\"********************************************************* .TP -.B --register-dns +.B \-\-register-dns Run ipconfig /flushdns and ipconfig /registerdns on connection initiation. This is known to kick Windows into recognizing pushed DNS servers. .\"********************************************************* .TP -.B --pause-exit +.B \-\-pause-exit Put up a "press any key to continue" message on the console prior to OpenVPN program exit. This option is automatically used by the Windows explorer when OpenVPN is run on a configuration file using the right-click explorer menu. .\"********************************************************* .TP -.B --service exit-event [0|1] +.B \-\-service exit-event [0|1] Should be used when OpenVPN is being automatically executed by another program in such a context that no interaction with the user via display or keyboard @@ -4785,26 +4786,26 @@ parameter. In any case, the controlling process can signal causing all such OpenVPN processes to exit. When executing an OpenVPN process using the -.B --service +.B \-\-service directive, OpenVPN will probably not have a console window to output status/error messages, therefore it is useful to use -.B --log +.B \-\-log or -.B --log-append +.B \-\-log-append to write these messages to a file. .\"********************************************************* .TP -.B --show-adapters +.B \-\-show-adapters (Standalone) Show available TAP-Win32 adapters which can be selected using the -.B --dev-node +.B \-\-dev-node option. On non-Windows systems, the .BR ifconfig (8) command provides similar functionality. .\"********************************************************* .TP -.B --allow-nonadmin [TAP-adapter] +.B \-\-allow-nonadmin [TAP-adapter] (Standalone) Set .B TAP-adapter @@ -4819,10 +4820,10 @@ and reloaded. This directive can only be used by an administrator. .\"********************************************************* .TP -.B --show-valid-subnets +.B \-\-show-valid-subnets (Standalone) Show valid subnets for -.B --dev tun +.B \-\-dev tun emulation. Since the TAP-Win32 driver exports an ethernet interface to Windows, and since TUN devices are point-to-point in nature, it is necessary for the TAP-Win32 driver @@ -4832,7 +4833,7 @@ Namely, the point-to-point endpoints used in TUN device emulation must be the middle two addresses of a /30 subnet (netmask 255.255.255.252). .\"********************************************************* .TP -.B --show-net +.B \-\-show-net (Standalone) Show OpenVPN's view of the system routing table and network adapter list. @@ -4840,12 +4841,12 @@ adapter list. .SS PKCS#11 Standalone Options: .\"********************************************************* .TP -.B --show-pkcs11-ids provider [cert_private] +.B \-\-show-pkcs11-ids provider [cert_private] (Standalone) Show PKCS#11 token object list. Specify cert_private as 1 if certificates are stored as private objects. -.B --verb +.B \-\-verb option can be used BEFORE this option to produce debugging information. .\"********************************************************* .SH SCRIPTING AND ENVIRONMENTAL VARIABLES @@ -4855,52 +4856,52 @@ of environmental variables for use by user-defined scripts. .SS Script Order of Execution .\"********************************************************* .TP -.B --up +.B \-\-up Executed after TCP/UDP socket bind and TUN/TAP open. .\"********************************************************* .TP -.B --tls-verify +.B \-\-tls-verify Executed when we have a still untrusted remote peer. .\"********************************************************* .TP -.B --ipchange +.B \-\-ipchange Executed after connection authentication, or remote IP address change. .\"********************************************************* .TP -.B --client-connect +.B \-\-client-connect Executed in -.B --mode server +.B \-\-mode server mode immediately after client authentication. .\"********************************************************* .TP -.B --route-up +.B \-\-route-up Executed after connection authentication, either immediately after, or some number of seconds after as defined by the -.B --route-delay +.B \-\-route-delay option. .\"********************************************************* .TP -.B --client-disconnect +.B \-\-client-disconnect Executed in -.B --mode server +.B \-\-mode server mode on client instance shutdown. .\"********************************************************* .TP -.B --down +.B \-\-down Executed after TCP/UDP and TUN/TAP close. .\"********************************************************* .TP -.B --learn-address +.B \-\-learn-address Executed in -.B --mode server +.B \-\-mode server mode whenever an IPv4 address/route or MAC address is added to OpenVPN's internal routing table. .\"********************************************************* .TP -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify Executed in -.B --mode server +.B \-\-mode server mode on new client connections, when the client is still untrusted. .\"********************************************************* @@ -4924,7 +4925,7 @@ Can string remapping be disabled? .B A: Yes, by using the -.B --no-name-remapping +.B \-\-no-name-remapping option, however this should be considered an advanced option. Here is a brief rundown of OpenVPN's current string types and the @@ -4940,17 +4941,17 @@ true. Alphanumeric, underbar ('_'), dash ('-'), dot ('.'), and at ('@'). -.B --auth-user-pass username: +.B \-\-auth-user-pass username: Same as Common Name, with one exception: starting with OpenVPN 2.0.1, the username is passed to the OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY plugin in its raw form, without string remapping. -.B --auth-user-pass password: +.B \-\-auth-user-pass password: Any "printable" character except CR or LF. Printable is defined to be a character which will cause the C library isprint() function to return true. -.B --client-config-dir filename as derived from common name or username: +.B \-\-client-config-dir filename as derived from common name or username: Alphanumeric, underbar ('_'), dash ('-'), and dot ('.') except for "." or ".." as standalone strings. As of 2.0.1-rc6, the at ('@') character has been added as well for compatibility with the common name character class. @@ -4980,45 +4981,45 @@ which refer to different client instances. .B bytes_received Total number of bytes received from client during VPN session. Set prior to execution of the -.B --client-disconnect +.B \-\-client-disconnect script. .\"********************************************************* .TP .B bytes_sent Total number of bytes sent to client during VPN session. Set prior to execution of the -.B --client-disconnect +.B \-\-client-disconnect script. .\"********************************************************* .TP .B common_name The X509 common name of an authenticated client. Set prior to execution of -.B --client-connect, --client-disconnect, +.B \-\-client-connect, \-\-client-disconnect, and -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify scripts. .\"********************************************************* .TP .B config Name of first -.B --config +.B \-\-config file. Set on program initiation and reset on SIGHUP. .\"********************************************************* .TP .B daemon Set to "1" if the -.B --daemon +.B \-\-daemon directive is specified, or "0" otherwise. Set on program initiation and reset on SIGHUP. .\"********************************************************* .TP .B daemon_log_redirect Set to "1" if the -.B --log +.B \-\-log or -.B --log-append +.B \-\-log-append directives are specified, or "0" otherwise. Set on program initiation and reset on SIGHUP. .\"********************************************************* @@ -5027,30 +5028,30 @@ Set on program initiation and reset on SIGHUP. The actual name of the TUN/TAP device, including a unit number if it exists. Set prior to -.B --up +.B \-\-up or -.B --down +.B \-\-down script execution. .\"********************************************************* .TP .B foreign_option_{n} An option pushed via -.B --push +.B \-\-push to a client which does not natively support it, such as -.B --dhcp-option +.B \-\-dhcp-option on a non-Windows system, will be recorded to this environmental variable sequence prior to -.B --up +.B \-\-up script execution. .\"********************************************************* .TP .B ifconfig_broadcast The broadcast address for the virtual ethernet segment which is derived from the -.B --ifconfig +.B \-\-ifconfig option when -.B --dev tap +.B \-\-dev tap is used. Set prior to OpenVPN calling the .I ifconfig @@ -5058,13 +5059,13 @@ or .I netsh (windows version of ifconfig) commands which normally occurs prior to -.B --up +.B \-\-up script execution. .\"********************************************************* .TP .B ifconfig_local The local VPN endpoint IP address specified in the -.B --ifconfig +.B \-\-ifconfig option (first parameter). Set prior to OpenVPN calling the .I ifconfig @@ -5072,15 +5073,15 @@ or .I netsh (windows version of ifconfig) commands which normally occurs prior to -.B --up +.B \-\-up script execution. .\"********************************************************* .TP .B ifconfig_remote The remote VPN endpoint IP address specified in the -.B --ifconfig +.B \-\-ifconfig option (second parameter) when -.B --dev tun +.B \-\-dev tun is used. Set prior to OpenVPN calling the .I ifconfig @@ -5088,16 +5089,16 @@ or .I netsh (windows version of ifconfig) commands which normally occurs prior to -.B --up +.B \-\-up script execution. .\"********************************************************* .TP .B ifconfig_netmask The subnet mask of the virtual ethernet segment that is specified as the second parameter to -.B --ifconfig +.B \-\-ifconfig when -.B --dev tap +.B \-\-dev tap is being used. Set prior to OpenVPN calling the .I ifconfig @@ -5105,61 +5106,61 @@ or .I netsh (windows version of ifconfig) commands which normally occurs prior to -.B --up +.B \-\-up script execution. .\"********************************************************* .TP .B ifconfig_pool_local_ip The local virtual IP address for the TUN/TAP tunnel taken from an -.B --ifconfig-push +.B \-\-ifconfig-push directive if specified, or otherwise from the ifconfig pool (controlled by the -.B --ifconfig-pool +.B \-\-ifconfig-pool config file directive). Only set for -.B --dev tun +.B \-\-dev tun tunnels. This option is set on the server prior to execution of the -.B --client-connect +.B \-\-client-connect and -.B --client-disconnect +.B \-\-client-disconnect scripts. .\"********************************************************* .TP .B ifconfig_pool_netmask The virtual IP netmask for the TUN/TAP tunnel taken from an -.B --ifconfig-push +.B \-\-ifconfig-push directive if specified, or otherwise from the ifconfig pool (controlled by the -.B --ifconfig-pool +.B \-\-ifconfig-pool config file directive). Only set for -.B --dev tap +.B \-\-dev tap tunnels. This option is set on the server prior to execution of the -.B --client-connect +.B \-\-client-connect and -.B --client-disconnect +.B \-\-client-disconnect scripts. .\"********************************************************* .TP .B ifconfig_pool_remote_ip The remote virtual IP address for the TUN/TAP tunnel taken from an -.B --ifconfig-push +.B \-\-ifconfig-push directive if specified, or otherwise from the ifconfig pool (controlled by the -.B --ifconfig-pool +.B \-\-ifconfig-pool config file directive). This option is set on the server prior to execution of the -.B --client-connect +.B \-\-client-connect and -.B --client-disconnect +.B \-\-client-disconnect scripts. .\"********************************************************* .TP @@ -5167,31 +5168,31 @@ scripts. The maximum packet size (not including the IP header) of tunnel data in UDP tunnel transport mode. Set prior to -.B --up +.B \-\-up or -.B --down +.B \-\-down script execution. .\"********************************************************* .TP .B local The -.B --local +.B \-\-local parameter. Set on program initiation and reset on SIGHUP. .\"********************************************************* .TP .B local_port The local port number, specified by -.B --port +.B \-\-port or -.B --lport. +.B \-\-lport. Set on program initiation and reset on SIGHUP. .\"********************************************************* .TP .B password The password provided by a connecting client. Set prior to -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify script execution only when the .B via-env modifier is specified, and deleted from the environment @@ -5200,23 +5201,23 @@ after the script returns. .TP .B proto The -.B --proto +.B \-\-proto parameter. Set on program initiation and reset on SIGHUP. .\"********************************************************* .TP .B remote_{n} The -.B --remote +.B \-\-remote parameter. Set on program initiation and reset on SIGHUP. .\"********************************************************* .TP .B remote_port_{n} The remote port number, specified by -.B --port +.B \-\-port or -.B --rport. +.B \-\-rport. Set on program initiation and reset on SIGHUP. .\"********************************************************* .TP @@ -5224,29 +5225,29 @@ Set on program initiation and reset on SIGHUP. The pre-existing default IP gateway in the system routing table. Set prior to -.B --up +.B \-\-up script execution. .\"********************************************************* .TP .B route_vpn_gateway The default gateway used by -.B --route +.B \-\-route options, as specified in either the -.B --route-gateway +.B \-\-route-gateway option or the second parameter to -.B --ifconfig +.B \-\-ifconfig when -.B --dev tun +.B \-\-dev tun is specified. Set prior to -.B --up +.B \-\-up script execution. .\"********************************************************* .TP .B route_{parm}_{n} A set of variables which define each route to be added, and are set prior to -.B --up +.B \-\-up script execution. .B parm @@ -5265,7 +5266,7 @@ or configuration file. Set to "init" or "restart" prior to up/down script execution. For more information, see documentation for -.B --up. +.B \-\-up. .\"********************************************************* .TP .B script_type @@ -5281,15 +5282,15 @@ Set prior to execution of any script. The reason for exit or restart. Can be one of .B sigusr1, sighup, sigterm, sigint, inactive (controlled by -.B --inactive +.B \-\-inactive option), .B ping-exit (controlled by -.B --ping-exit +.B \-\-ping-exit option), .B ping-restart (controlled by -.B --ping-restart +.B \-\-ping-restart option), .B connection-reset (triggered on TCP connection reset), @@ -5303,7 +5304,7 @@ or Client connection timestamp, formatted as a human-readable time string. Set prior to execution of the -.B --client-connect +.B \-\-client-connect script. .\"********************************************************* .TP @@ -5311,7 +5312,7 @@ script. The duration (in seconds) of the client session which is now disconnecting. Set prior to execution of the -.B --client-disconnect +.B \-\-client-disconnect script. .\"********************************************************* .TP @@ -5319,7 +5320,7 @@ script. Client connection timestamp, formatted as a unix integer date/time value. Set prior to execution of the -.B --client-connect +.B \-\-client-connect script. .\"********************************************************* .TP @@ -5329,7 +5330,7 @@ where .B n is the verification level. Only set for TLS connections. Set prior to execution of -.B --tls-verify +.B \-\-tls-verify script. .\"********************************************************* .TP @@ -5340,33 +5341,38 @@ where is the verification level. Only set for TLS connections. Set prior to execution of .B --tls-verify -script. +script. This is in the form of a hex string like "37AB46E0", which is +suitable for doing serial-based OCSP queries (with OpenSSL, you have +to prepend "0x" to the string). If something goes wrong while reading +the value from the certificate it will be an empty string, so your +code should check that. +See the contrib/OCSP_check/OCSP_check.sh script for an example. .\"********************************************************* .TP .B tun_mtu The MTU of the TUN/TAP device. Set prior to -.B --up +.B \-\-up or -.B --down +.B \-\-down script execution. .\"********************************************************* .TP .B trusted_ip Actual IP address of connecting client or peer which has been authenticated. Set prior to execution of -.B --ipchange, --client-connect, +.B \-\-ipchange, \-\-client-connect, and -.B --client-disconnect +.B \-\-client-disconnect scripts. .\"********************************************************* .TP .B trusted_port Actual port number of connecting client or peer which has been authenticated. Set prior to execution of -.B --ipchange, --client-connect, +.B \-\-ipchange, \-\-client-connect, and -.B --client-disconnect +.B \-\-client-disconnect scripts. .\"********************************************************* .TP @@ -5375,12 +5381,12 @@ Actual IP address of connecting client or peer which has not been authenticated yet. Sometimes used to .B nmap the connecting host in a -.B --tls-verify +.B \-\-tls-verify script to ensure it is firewalled properly. Set prior to execution of -.B --tls-verify +.B \-\-tls-verify and -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify scripts. .\"********************************************************* .TP @@ -5388,16 +5394,16 @@ scripts. Actual port number of connecting client or peer which has not been authenticated yet. Set prior to execution of -.B --tls-verify +.B \-\-tls-verify and -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify scripts. .\"********************************************************* .TP .B username The username provided by a connecting client. Set prior to -.B --auth-user-pass-verify +.B \-\-auth-user-pass-verify script execution only when the .B via-env modifier is specified. @@ -5409,7 +5415,7 @@ where .B n is the verification level. Only set for TLS connections. Set prior to execution of -.B --tls-verify +.B \-\-tls-verify script. This variable is similar to .B tls_id_{n} except the component X509 subject fields are broken out, and @@ -5453,30 +5459,30 @@ Like except don't re-read configuration file, and possibly don't close and reopen TUN/TAP device, re-read key files, preserve local IP address/port, or preserve most recently authenticated remote IP address/port based on -.B --persist-tun, --persist-key, --persist-local-ip, +.B \-\-persist-tun, \-\-persist-key, \-\-persist-local-ip, and -.B --persist-remote-ip +.B \-\-persist-remote-ip options respectively (see above). This signal may also be internally generated by a timeout condition, governed by the -.B --ping-restart +.B \-\-ping-restart option. This signal, when combined with -.B --persist-remote-ip, +.B \-\-persist-remote-ip, may be sent when the underlying parameters of the host's network interface change such as when the host is a DHCP client and is assigned a new IP address. See -.B --ipchange +.B \-\-ipchange above for more information. .\"********************************************************* .TP .B SIGUSR2 Causes OpenVPN to display its current statistics (to the syslog file if -.B --daemon +.B \-\-daemon is used, or stdout otherwise). .\"********************************************************* .TP @@ -5531,7 +5537,7 @@ If firewalls exist between the two machines, they should be set to forward UDP port 1194 in both directions. If you do not have control over the firewalls between the two machines, you may still be able to use OpenVPN by adding -.B --ping 15 +.B \-\-ping 15 to each of the .B openvpn commands used below in the examples (this will cause each peer to send out @@ -5600,11 +5606,11 @@ you will get a weird feedback loop. .LP On may: .IP -.B openvpn --remote june.kg --dev tun1 --ifconfig 10.4.0.1 10.4.0.2 --verb 9 +.B openvpn \-\-remote june.kg \-\-dev tun1 \-\-ifconfig 10.4.0.1 10.4.0.2 \-\-verb 9 .LP On june: .IP -.B openvpn --remote may.kg --dev tun1 --ifconfig 10.4.0.2 10.4.0.1 --verb 9 +.B openvpn \-\-remote may.kg \-\-dev tun1 \-\-ifconfig 10.4.0.2 10.4.0.1 \-\-verb 9 .LP Now verify the tunnel is working by pinging across the tunnel. .LP @@ -5617,17 +5623,17 @@ On june: .B ping 10.4.0.1 .LP The -.B --verb 9 +.B \-\-verb 9 option will produce verbose output, similar to the .BR tcpdump (8) program. Omit the -.B --verb 9 +.B \-\-verb 9 option to have OpenVPN run quietly. .\"********************************************************* .SS Example 2: A tunnel with static-key security (i.e. using a pre-shared secret) First build a static key on may. .IP -.B openvpn --genkey --secret key +.B openvpn \-\-genkey \-\-secret key .LP This command will build a random key file called .B key @@ -5641,11 +5647,11 @@ program. .LP On may: .IP -.B openvpn --remote june.kg --dev tun1 --ifconfig 10.4.0.1 10.4.0.2 --verb 5 --secret key +.B openvpn \-\-remote june.kg \-\-dev tun1 \-\-ifconfig 10.4.0.1 10.4.0.2 \-\-verb 5 \-\-secret key .LP On june: .IP -.B openvpn --remote may.kg --dev tun1 --ifconfig 10.4.0.2 10.4.0.1 --verb 5 --secret key +.B openvpn \-\-remote may.kg \-\-dev tun1 \-\-ifconfig 10.4.0.2 10.4.0.1 \-\-verb 5 \-\-secret key .LP Now verify the tunnel is working by pinging across the tunnel. .LP @@ -5667,10 +5673,10 @@ as the TLS server. First, build a separate certificate/key pair for both may and june (see above where -.B --cert +.B \-\-cert is discussed for more info). Then construct Diffie Hellman parameters (see above where -.B --dh +.B \-\-dh is discussed for more info). You can also use the included test files client.crt, client.key, server.crt, server.key and ca.crt. @@ -5683,11 +5689,11 @@ parameters you can use the included file dh1024.pem. .LP On may: .IP -.B openvpn --remote june.kg --dev tun1 --ifconfig 10.4.0.1 10.4.0.2 --tls-client --ca ca.crt --cert client.crt --key client.key --reneg-sec 60 --verb 5 +.B openvpn \-\-remote june.kg \-\-dev tun1 \-\-ifconfig 10.4.0.1 10.4.0.2 \-\-tls-client \-\-ca ca.crt \-\-cert client.crt \-\-key client.key \-\-reneg-sec 60 \-\-verb 5 .LP On june: .IP -.B openvpn --remote may.kg --dev tun1 --ifconfig 10.4.0.2 10.4.0.1 --tls-server --dh dh1024.pem --ca ca.crt --cert server.crt --key server.key --reneg-sec 60 --verb 5 +.B openvpn \-\-remote may.kg \-\-dev tun1 \-\-ifconfig 10.4.0.2 10.4.0.1 \-\-tls-server \-\-dh dh1024.pem \-\-ca ca.crt \-\-cert server.crt \-\-key server.key \-\-reneg-sec 60 \-\-verb 5 .LP Now verify the tunnel is working by pinging across the tunnel. .LP @@ -5700,16 +5706,16 @@ On june: .B ping 10.4.0.1 .LP Notice the -.B --reneg-sec 60 +.B \-\-reneg-sec 60 option we used above. That tells OpenVPN to renegotiate the data channel keys every minute. Since we used -.B --verb 5 +.B \-\-verb 5 above, you will see status information on each new key negotiation. For production operations, a key renegotiation interval of 60 seconds is probably too frequent. Omit the -.B --reneg-sec 60 +.B \-\-reneg-sec 60 option to use OpenVPN's default key renegotiation interval of one hour. .\"********************************************************* .SS Routing: @@ -5745,7 +5751,7 @@ over the secure tunnel (or vice versa). In a production environment, you could put the route command(s) in a shell script and execute with the -.B --up +.B \-\-up option. .\"********************************************************* .SH FIREWALLS @@ -5753,7 +5759,7 @@ OpenVPN's usage of a single UDP port makes it fairly firewall-friendly. You should add an entry to your firewall rules to allow incoming OpenVPN packets. On Linux 2.4+: .IP -.B iptables -A INPUT -p udp -s 1.2.3.4 --dport 1194 -j ACCEPT +.B iptables -A INPUT -p udp -s 1.2.3.4 \-\-dport 1194 -j ACCEPT .LP This will allow incoming packets on UDP port 1194 (OpenVPN's default UDP port) from an OpenVPN peer at 1.2.3.4. @@ -5764,7 +5770,7 @@ address can be considered optional, since HMAC packet authentication is a much more secure method of verifying the authenticity of a packet source. In that case: .IP -.B iptables -A INPUT -p udp --dport 1194 -j ACCEPT +.B iptables -A INPUT -p udp \-\-dport 1194 -j ACCEPT .LP would be adequate and would not render the host inflexible with respect to its peer having a dynamic IP address. @@ -5773,7 +5779,7 @@ OpenVPN also works well on stateful firewalls. In some cases, you may not need to add any static rules to the firewall list if you are using a stateful firewall that knows how to track UDP connections. If you specify -.B --ping n, +.B \-\-ping n, OpenVPN will be guaranteed to send a packet to its peer at least once every .B n |