ip forwarding

[Andrew Critchlow <a_critchlow@hotmail.com>]

Hi everyone, I am having some problems either understanding ip forarding or configuring it?
 
My set up is:
 
XP1 - Debian/Server - XP2
 
XP1 IP = 10.251.134.20
Debian/Server eth0 = 10.251.134.10
Debian/Server eth1 = 172.16.0.50
XP2 IP = 172.16.0.10
 
I want XP1 to be able to ping XP2, so I enabled IP forwarding in /etc/network/options
Unfortunately XP1 still can not ping XP2.
(XP1 can ping Debian/Server, and Debian/Server can ping XP2)
 
 
Do I have to do anything else to enable the Debian/Server to act as a simple router?
 
 
 
 
 
Thanks all.
 
Andrew.