[CentOS] how to reroute all ADSL traffic via another server on theinternet?

[Dan Irwin]

>-----Original Message-----
>From: centos-bounces at centos.org 
>[mailto:centos-bounces at centos.org] On Behalf Of Rudi Ahlers
>Sent: Wednesday, 28 April 2010 11:11 PM
>To: CentOS mailing list
>Subject: [CentOS] how to reroute all ADSL traffic via another 
>server on theinternet?
>
>Hi all,
>
>Does anyone know, if it's possible to reroute all (i.e. HTTP / FTP /
>DNS / SMTP / POP3 / IMAP / etc) from an ADSL connected machine via
>another server, which is currently hosted with IS and has full
>internet access?
>
>
>i.e. Can I setup another machine, on a different public IP than the
>dynamic ADSL IP as default gw? OR do I need todo something on that
>machine to work as a router for such a setup?
>
>Both servers in this case is CentOS linux, but I'm sure that won't
>make a big difference?
>

You could use GRE tunnelling, which is supported by Linux and Cisco
among others.

You could set up a GRE tunnel between your two sites, assign a /30 for
the link, and route most traffic over the GRE interface (Minus the IP
Address of your remote site - it must be routed via your internet
connection).

This will behave as a point-to-point link between your sites.

Check out the ip(8) command, in particular the ip tunnel commands.

But, something like this should be a nice start:

 ip tunnel add Tunnel0 mode GRE remote 1.2.3.4

 ifconfig Tunnel0 10.10.10.1 netmask 255.255.255.252

 ip route add 1.2.3.4/32 via 6.7.8.9

Cheers,

Dan