man vpnc (Administration système) - client for Cisco VPN3000 Concentrator, IOS and PIX
NAME
vpnc - client for Cisco VPN3000 Concentrator, IOS and PIX
SYNOPSIS
see vpnc --long-help
DESCRIPTION
This manual page documents briefly the vpnc, vpnc-connect and vpnc-disconnect commands.
vpnc is a VPN client for the Cisco 3000 VPN Concentrator, creating a IPSec-like connection as a tunneling network device for the local system. It uses the TUN/TAP driver in Linux kernel 2.4 and above and device tun(4) on BSD. The created connection is presented as a tunneling network device to the local system.
OBLICATORY WARNING: the most used configuration (XAUTH authentication) is insecure by design, be aware of this fact when you use vpnc to exchange sensitive data like passwords!
OBLICATORY WARNING: the most used configuration (XAUTH authentication) is insecure by design, be aware of this fact when you use vpnc to exchange sensitive data like passwords!
The vpnc daemon by it self does not set any routes, the user (or the connect script, see below) has to do it on its own, e.g. for a full tunnel with IP routing under Linux. Further, the user must care about setting a minimal route to the gateway to not cut the essential connection.
However, when connection has been established, vpnc will run a simple command (see --script) to configure the interface and care about the route setup. By default, only a simple ifconfig command is executed.
The command vpnc-connect is a helper script that will assist on connection invocation and routing configuration. It can also be used to manage configuration files for multiple VPN connections. The script can be started by the user or from the daemon (see --script) when the connection is established. In the first case, it will simply run the daemon after some environment checks. When executed by the daemon later, it will create a minimalistic host route to the gateway and configures the default gateway configuration of Linux to run over the VPN tunnel.
The vpnc-disconnect command is used to terminate the connection previously created by vpnc-connect and restore the previous routing configuration.
CONFIGURATION
The daemon reads configuration data from the following places:
- - command line options
- - config file(s) specified on the command line
- - /etc/vpnc/default.conf
- - /etc/vpnc.conf
- - prompting the user if not found above
The vpnc-connect script expects the configuration file as the first parameter. This can either be an absolute path or the name of a config file located in /etc/vpnc/<filename>.conf. If no config is specified, vpnc-connect will try to load /etc/vpnc/default.conf or as a last resort /etc/vpnc.conf.
OPTIONS
The program options can be either given as argument (but not all of them for security reasons) or be stored in a configuration file.
- --print-config
- Prints your configuration; output can be used as vpnc.conf
See output of vpnc --long-help for a complete description
FILES
/etc/vpnc.conf The default configuration file. You can specify the same config directives as with command line options and additionaly IPSec secret and Xauth password both supplying a cleartext password. Scrambled passwords from the Cisco configuration profiles are not supported.
See EXAMPLES for further details.
/etc/vpnc/*.conf The vpnc-connect will read configuration files in this directory when the config script name (without .conf) is specified on the command line.
EXAMPLES
This is an example vpnc.conf:
IPSec gateway vpn.rwth-aachen.de
IPSec ID MoPS
IPSec secret mopsWLAN
Xauth username abcdef
Xauth password 123456
The lines begin with a keyword (no leading spaces!). The values start exactly one space after the keywords, and run to the end of line. This lets you put any kind of weird character (except CR, LF and NUL) in your strings, but it does mean you can't add comments after a string, or spaces before them.
See also the --print-config option to generate a config file, and the example file in the package documentation directory where more advanced usage is demonstrated.
Advanced features like manual setting of multiple target routes is documented in the example files of the vpnc package.
ADVANCED USAGE
The vpnc-connect stript shipped with Debian has some additional features:
- Custom route setting
- By default, the default route is deleted after connection and replaced with the new one (going trough the VPN tunnel device). However, some people wish to limit the target address range to few IP ranges. This can be done using the config directive Target networks in the config file. For example: Target networks 123.234.210.0/24 10.1.0.0/16
- Multiple config profiles management
- You can have multiple config files and select one on connection by specifying a short profile name instead of a config file path. In this case, the file /etc/vpnc/PROFILE.conf is used as config file (where PROFILE is the short profile name).
- /etc/resolv.conf update
- If the package resolvconf is installed and the VPN gateway sends some DNS server data, the script will use resolution to integrate the received data into /etc/resolv.conf. To disable this behaviour, set the config directive DNSUpdate to the no value.
ADVANCED USAGE
The vpnc-connect stript shipped with Debian has some additional features:
- Custom route setting
- By default, the default route is deleted after connection and replaced with the new one (going trough the VPN tunnel device). However, some people wish to limit the target address range to few IP ranges. This can be done using the config directive Target networks in the config file. For example: Target networks 123.234.210.0/24 10.1.0.0/16
- Multiple config profiles management
- You can have multiple config files and select one on connection by specifying a short profile name instead of a config file path. In this case, the file /etc/vpnc/PROFILE.conf is used as config file (where PROFILE is the short profile name).
- /etc/resolv.conf update
- If the package resolvconf is installed and the VPN gateway sends some DNS server data, the script will use resolution to integrate the received data into /etc/resolv.conf. To disable this behaviour, set the config directive DNSUpdate to the no value.
TODO
Re-keying is not implemented yet (default rekey-intervall is 8 hours).
Certificate support (Pre-Shared-Key + XAUTH is known to be insecure).
AUTHOR
This man-page has been written by Eduard Bloch <blade(at)debian.org> and Christian Lackas <delta(at)lackas.net>, based on vpnc README by Maurice Massar <vpnc(at)unix-ag.uni-kl.de>. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License, Version 2 any later version published by the Free Software Foundation.
On Debian systems, the complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL.