diff options
Diffstat (limited to 'doc/openvpn.8')
| -rw-r--r-- | doc/openvpn.8 | 141 |
1 files changed, 103 insertions, 38 deletions
diff --git a/doc/openvpn.8 b/doc/openvpn.8 index b914f32..a504ce9 100644 --- a/doc/openvpn.8 +++ b/doc/openvpn.8 @@ -343,6 +343,13 @@ below), then are discarded. .sp The downside of using \fB\-\-mlock\fP is that it will reduce the amount of physical memory available to other applications. +.sp +The limit on how much memory can be locked and how that limit +is enforced are OS\-dependent. On Linux the default limit that an +unprivileged process may lock (RLIMIT_MEMLOCK) is low, and if +privileges are dropped later, future memory allocations will very +likely fail. The limit can be increased using ulimit or systemd +directives depending on how OpenVPN is started. .TP .BI \-\-nice \ n Change process priority after initialization (\fBn\fP greater than 0 is @@ -1268,50 +1275,67 @@ next remote succeeds. To silently ignore an option pushed by the server, use \fBignore\fP\&. .TP .BI \-\-remote \ args -Remote host name or IP address. It supports two additional optional -arguments: \fBport\fP and \fBproto\fP\&. On the client, multiple \fB\-\-remote\fP -options may be specified for redundancy, each referring to a different -OpenVPN server. Specifying multiple \fB\-\-remote\fP options for this -purpose is a special case of the more general connection\-profile -feature. See the \fB<connection>\fP documentation below. -.sp -The OpenVPN client will try to connect to a server at \fBhost:port\fP in -the order specified by the list of \fB\-\-remote\fP options. +Remote host name or IP address, port and protocol. .sp -Examples: +Valid syntaxes: .INDENT 7.0 .INDENT 3.5 .sp .nf .ft C -remote server.example.net -remote server.example.net 1194 -remote server.example.net tcp +remote host +remote host port +remote host port proto .ft P .fi .UNINDENT .UNINDENT .sp -\fBproto\fP indicates the protocol to use when connecting with the remote, -and may be \fBtcp\fP or \fBudp\fP\&. +The \fBport\fP and \fBproto\fP arguments are optional. The OpenVPN client +will try to connect to a server at \fBhost:port\fP\&. The \fBproto\fP argument +indicates the protocol to use when connecting with the remote, and may be +\fBtcp\fP or \fBudp\fP\&. To enforce IPv4 or IPv6 connections add a +\fB4\fP or \fB6\fP suffix; like \fBudp4\fP / \fBudp6\fP +/ \fBtcp4\fP / \fBtcp6\fP\&. .sp -For forcing IPv4 or IPv6 connection suffix tcp or udp with 4/6 like -udp4/udp6/tcp4/tcp6. +On the client, multiple \fB\-\-remote\fP options may be specified for +redundancy, each referring to a different OpenVPN server, in the order +specified by the list of \fB\-\-remote\fP options. Specifying multiple +\fB\-\-remote\fP options for this purpose is a special case of the more +general connection\-profile feature. See the \fB<connection>\fP +documentation below. .sp The client will move on to the next host in the list, in the event of connection failure. Note that at any given time, the OpenVPN client will at most be connected to one server. .sp -Note that since UDP is connectionless, connection failure is defined by +Examples: +.INDENT 7.0 +.INDENT 3.5 +.sp +.nf +.ft C +remote server1.example.net +remote server1.example.net 1194 +remote server2.example.net 1194 tcp +.ft P +.fi +.UNINDENT +.UNINDENT +.INDENT 7.0 +.TP +.B \fINote:\fP +Since UDP is connectionless, connection failure is defined by the \fB\-\-ping\fP and \fB\-\-ping\-restart\fP options. .sp -Note the following corner case: If you use multiple \fB\-\-remote\fP -options, AND you are dropping root privileges on the client with -\fB\-\-user\fP and/or \fB\-\-group\fP 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 the -necessary privileges to close and reopen the TUN/TAP interface. This -could cause the client to exit with a fatal error. +Also, if you use multiple \fB\-\-remote\fP options, AND you are dropping +root privileges on the client with \fB\-\-user\fP and/or \fB\-\-group\fP 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 the necessary privileges to +close and reopen the TUN/TAP interface. This could cause the client +to exit with a fatal error. +.UNINDENT .sp If \fB\-\-remote\fP is unspecified, OpenVPN will listen for packets from any IP address, but will not act on those packets unless they pass all @@ -1709,7 +1733,8 @@ ifconfig\-ipv6\-pool ipv6addr/bits .UNINDENT .sp The pool starts at \fBipv6addr\fP and matches the offset determined from -the start of the IPv4 pool. +the start of the IPv4 pool. If the host part of the given IPv6 +address is \fB0\fP, the pool starts at \fBipv6addr\fP +1. .TP .BI \-\-ifconfig\-pool\-persist \ args Persist/unpersist ifconfig\-pool data to \fBfile\fP, at \fBseconds\fP @@ -2098,6 +2123,14 @@ Don\(aqt inherit the global push list for a specific client instance. Specify this option in a client\-specific context such as with a \fB\-\-client\-config\-dir\fP configuration file. This option will ignore \fB\-\-push\fP options at the global config file level. +.sp +\fINOTE\fP: \fB\-\-push\-reset\fP is very thorough: it will remove almost +all options from the list of to\-be\-pushed options. In many cases, +some of these options will need to be re\-configured afterwards \- +specifically, \fB\-\-topology subnet\fP and \fB\-\-route\-gateway\fP will get +lost and this will break client configs in many cases. Thus, for most +purposes, \fB\-\-push\-remove\fP is better suited to selectively remove +push options for individual clients. .TP .BI \-\-server \ args A helper directive designed to simplify the configuration of OpenVPN\(aqs @@ -2242,6 +2275,26 @@ tls\-server .UNINDENT .UNINDENT .TP +.BI \-\-server\-ipv6 \ args +Convenience\-function to enable a number of IPv6 related options at once, +namely \fB\-\-ifconfig\-ipv6\fP, \fB\-\-ifconfig\-ipv6\-pool\fP and +\fB\-\-push tun\-ipv6\fP\&. +.sp +Valid syntax: +.INDENT 7.0 +.INDENT 3.5 +.sp +.nf +.ft C +server\-ipv6 ipv6addr/bits +.ft P +.fi +.UNINDENT +.UNINDENT +.sp +Pushing of the \fB\-\-tun\-ipv6\fP directive is done for older clients which +require an explicit \fB\-\-tun\-ipv6\fP in their configuration. +.TP .BI \-\-stale\-routes\-check \ args Remove routes which haven\(aqt had activity for \fBn\fP seconds (i.e. the ageing time). This check is run every \fBt\fP seconds (i.e. check interval). @@ -2264,9 +2317,15 @@ This option helps to keep the dynamic routing table small. See also \fB\-\-max\-routes\-per\-client\fP .TP .B \-\-username\-as\-common\-name -For \fB\-\-auth\-user\-pass\-verify\fP authentication, use the authenticated -username as the common name, rather than the common name from the client -cert. +Use the authenticated username as the common\-name, rather than the +common\-name from the client certificate. Requires that some form of +\fB\-\-auth\-user\-pass\fP verification is in effect. As the replacement happens +after \fB\-\-auth\-user\-pass\fP verification, the verification script or +plugin will still receive the common\-name from the certificate. +.sp +The common_name environment variable passed to scripts and plugins invoked +after authentication (e.g, client\-connect script) and file names parsed in +client\-config directory will match the username. .TP .BI \-\-verify\-client\-cert \ mode Specify whether the client is required to supply a valid certificate. @@ -4271,6 +4330,10 @@ dhcp\-options type [parm] .B \fBDOMAIN\fP \fBname\fP Set Connection\-specific DNS Suffix to \fBname\fP\&. .TP +.B \fBADAPTER_DOMAIN_SUFFIX\fP \fBname\fP +Alias to \fBDOMAIN\fP\&. This is a compatibility option, it +should not be used in new deployments. +.TP .B \fBDOMAIN\-SEARCH\fP \fBname\fP Add \fBname\fP to the domain search list. Repeat this option to add more entries. Up to @@ -5020,9 +5083,8 @@ plugins will be called on client instance object deletion, even in cases where some of the related client\-connect functions returned an error status. .sp -The \fB\-\-client\-disconnect\fP command is passed the same pathname as the -corresponding \fB\-\-client\-connect\fP command as its last argument (after -any arguments specified in \fBcmd\fP). +The \fB\-\-client\-disconnect\fP command is not passed any extra arguments +(only those arguments specified in cmd, if any). .TP .BI \-\-down \ cmd Run command \fBcmd\fP after TUN/TAP device close (post \fB\-\-user\fP UID @@ -5632,10 +5694,10 @@ command line or configuration file. A set of variables which define each IPv6 route to be added, and are set prior to \fB\-\-up\fP script execution. .sp -\fBparm\fP will be one of \fBnetwork\fP or \fBgateway\fP -(\fBnetmask\fP is contained as \fB/nnn\fP in the -\fBroute_ipv6_network_{n}\fP, unlike IPv4 where it is passed in a -separate environment variable). +\fBparm\fP will be one of \fBnetwork\fP, \fBgateway\fP or +\fBmetric\fP\&. \fBroute_ipv6_network_{n}\fP contains \fBnetmask\fP +as \fB/nnn\fP, unlike IPv4 where it is passed in a separate environment +variable. .sp \fBn\fP is the OpenVPN route number, starting from 1. .sp @@ -6283,8 +6345,11 @@ Valid syntax: .UNINDENT .UNINDENT .sp -If an IPv6 target address is passed as argument, the IPv6 route for this -host is reported. +For IPv6 this queries the route towards ::/128, or the specified IPv6 +target address if passed as argument. +For IPv4 on Linux, Windows, MacOS and BSD it looks for a 0.0.0.0/0 route. +If there are more specific routes, the result will not always be matching +the route of the IPv4 packets to the VPN gateway. .UNINDENT .SS Advanced Expert Options .sp |