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Diffstat (limited to 'openvpn/contrib/openvpn-fwmarkroute-1.00/README')
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diff --git a/openvpn/contrib/openvpn-fwmarkroute-1.00/README b/openvpn/contrib/openvpn-fwmarkroute-1.00/README new file mode 100644 index 00000000..66fe61ad --- /dev/null +++ b/openvpn/contrib/openvpn-fwmarkroute-1.00/README @@ -0,0 +1,44 @@ +OpenVPN fwmark Routing +Sean Reifschneider, <jafo@tummy.com> +Thursday November 27, 2003 +========================== + +These scripts can be used with OpenVPN up and down scripts to set up +routing on a Linux system such that the VPN traffic is sent via normal +network connectivity, but other traffic to that network runs over the VPN. +The idea is to allow encryption of data to the network the remote host is +on, without interfering with the VPN traffic. You can't simply add a route +to the remote network, becaues that will cause the VPN traffic to also try +to run over the VPN, and breaks the VPN. + +These scripts use the Linux "fwmark" iptables rules to specify routing +based not only on IP address, but also by port and protocol. This allows +you to effectively say "if the packet is to this IP address on this port +using this protocol, then use the normal default gateway, otherwise use the +VPN gateway. + +This is set up on the client VPN system, not the VPN server. These scripts +also set up all ICMP echo-responses to run across the VPN. You can +comment the lines in the scripts to disable this, but I find this useful +at coffee shops which have networks that block ICMP. + +To configure this, you need to set up these scripts as your up and down +scripts in the config file. You will need to set these values in the +config file: + + up /etc/openvpn/fwmarkroute.up + down /etc/openvpn/fwmarkroute.down + up-restart + up-delay + + setenv remote_netmask_bits 24 + +Note: For this to work, you can't set the "user" or "group" config options, +because then the scripts will not run as root. + +The last setting allows you to control the size of the network the remote +system is on. The remote end has to be set up to route, probably with +masquerading or NAT. The network this netmask relates to is calculated +using the value of "remote" in the conf file. + +Sean |