VPN outgoing traffic; select eth

dnwk

I have a server that use StrongSwan as VPN server. I have two IPs. How do I select which IP to use as out going traffic?
Thanks

CFarence

Was OS is it running? Easiest way is to have only one gateway. I have some servers that have a VPN connected and I don't want regular internet traffic going through the VPN. So for the VPN's interface I don't put a gateway.

Twinker

iptables and then you can choose the output interface or you can use SNAT with --to-source

dnwk

It is Ubuntu 14. I have two IPs/eth. I want VPN user to connect to IP1. However, I want their outgoing traffic(visiting other website through VPN) using 2nd IP.

dnwk

How to modify this Iptables to define the outgoing eth?
iptables --table nat --append POSTROUTING --jump MASQUERADE

howardsl2

@dnwk said:

iptables -t nat -A POSTROUTING -s VPN_SUBNET_CIDR -o eth+ -j SNAT --to-source VPN_SERVER_2nd_IP

Also in /etc/ipsec.conf, try adding this line: leftnexthop=Gateway_of_2nd_IP