[strongSwan] Customizing routing

Tobias Brunner tobias at strongswan.org
Tue Dec 15 11:00:11 CET 2015

Hi Jan,

> With kernel-netlink however I can achieve higher throughput with less
> CPU being used, but in that case SNAT seems to fail sometimes
> (connections are initiated correctly but "hang" after a while). Main
> difference is the lack of dedicated interface so routing customization
> is not required, but below SNAT rule seems to result in hanging
> connections:
> iptables -t nat -A POSTROUTING -o WAN -d A,B -j SNAT --to-source <virtual-ip>

This is about the same rule that's used in the updown script in [1].  It
might help if you tried to debug what happens in Netfilter via the TRACE
target (see e.g. [2]).


[1] https://www.strongswan.org/testing/testresults/ikev1/nat-virtual-ip/
[2] http://backreference.org/2010/06/11/iptables-debugging/

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