[LARTC] Policy based routing support for IPv6 in Linux

[B.A.Kock@telecom.tno.nl]

Hi all,

I have a dual stacked (IPv4/IPv6) Linux host (S) with two interfaces =
that can both be used to reach a destination (D) and are both up. In =
order to make sure a packet is transmitted over the correct interface I =
use policy based routing to choose the correct routing table based on =
the IP source address.

The network setup is shown below:


   |---|
   | D |
   |---|
     | =20
     |
   |---|
   | R |
   |---|
    / \
   /   \
 |-------|
 |   S   |
 |-------|
 =20
The two interfaces of S both reside in a different IP subnet.

For IPv4 this works ok, but IPv6 does not seem to interact with the =
Routing Policy DataBase (RPDB) as explained in =
http://www.policyrouting.org/PolicyRoutingBook/ONLINE/CH09.web.html =
section 9.2. Here it is stated that this might be solved in the later =
releases of the Linux kernel 2.5 and further. I am using RH 9 =
(2.4.20-8), 2.4 based kernel so that might explain why it does not work =
but before I decide to move to a newer kernel release I hope someone can =
help me answer the following questions:

1. Does anyone know if Policy Based Routing in the way it is used here =
is supported by the newer Linux kernels for IPv6?
2. Can anyone think of another solution for this?

Greetz,

Boris Kock