[CentOS] OT: routing between eth0 and ppp0 WITHOUT NAT

On 3/13/06, James Pifer <jep at obrien-pifer.com> wrote:
>
> I'm trying to setup linux as a router instead of a MASQ/NAT over a VPN.
> So I'm trying to "connect" to private networks using the VPN as the
> conduit.

I presume you have set

net.ipv4.ip_forward = 1

in /etc/sysctl.conf ?

You also need to make appropriate entries in
/etc/sysconfig/network-scripts/route-eth0 and
/etc/sysconfig/network-scripts/route-ppp0.  I don't think you need to
do anything with iptables at all if sysctl.conf and the routes are set
correctly.

See /usr/share/doc/kernel-doc-2.6.9/Documentation/networking/ip-sysctl.txt
and also /usr/share/doc/initscripts-7.93.24.EL/sysconfig.txt for
details.