On 2014-12-26 17:58, Arno Verhoeven wrote: [..]
But it doesn't work because my server routes the replies to my ISP's Gw where they get source filtered.
Good ISP they should filter based on source addresses :)
And you partially have your answer in that sentence too: source based routing
Check for instance: http://tldp.org/HOWTO/Adv-Routing-HOWTO/lartc.rpdb.simple.html
Which is a simple example.
(In IPv6 one can do it simpler with the 'src' attribute, but unfortunately they did not bring that to IPv4...)
Greets, Jeroen