Something like next hop match

[Markus Marquardt <markus.marquardt@atosorigin.com>]

Hello,

in my configuration there's a linux router which is dynamically learning
routes via RIP from an isdn router connected to the "outside" interface
of the router. The internet gateway is also conencted to that interface.

For some reason i don't want the packets which travel through the isdn
router to get SNATted. Packets going out to the internet gateway must be
SNATted.

Is there any way to match the packets which travel through the isdn
router by something like a next hop match in the POSTROUTING table? Some
years ago there was a nexthop match patch, but it never makes it into
the netfilter project.

Any ideas?

Regards,
Markus