[strongSwan] Problem connecting to a Cisco Unity gateway

[Tobias Brunner]

Hi Bas,

> So am I right that the only thing left to do is configure my system so
> that packets to hosts on the 10.180.0.0/24 subnet appear to come from
> a host on the 172.16.48.16/28 subnet?
> 
> To accomplish this I already added the additional IP address
> 172.16.48.16 to my NIC (besides the DHCP configured 192.168.42.162).
> 
> What's the next step? Do I need to add a route or some iptables rule?

strongSwan should find the address you added to the NIC and install an
appropriate route to routing table 220 automatically.  You may check
with `ip route list table 220`.  This route will look similar to this:

  10.180.0.0/16 via <default GW> dev eth0 proto static src 172.16.48.16

This should force 172.16.48.16 as source address for packets sent to
hosts in 10.180.0.0/16.  (Depending on how the other peer is configured
you might want to try a different IP from your source subnet e.g. .17,
because .16 is the network ID, while .31 is the broadcast address).

Regards,
Tobias