iptables for backup connection

iptables for backup connection

[david]

Dear all,
In my office i using 2 connection (Wireless connection direct to ISP "A"
and backup connection to ISP "B" with ADSL Modem), how to configure Linux
iptables (gateway) so when connection to ISP "A" down client can still
work with ISP "B" without reconfiguration at client computer (see network
diagram B).


Network diagram "A" (current)
=============================

     ISP "A"
       :
       :
       :
       \/
:-----------------:
:LINUX ROUTER/GW  :
:eth0 202.x.x.1   :
:eth1 172.16.x.100:
:-----------------:
       /\
       :
       :
       \/
:-----------------:
:Client computer's:
:-----------------:
       /\
       :
       :
       \/
:--------------------:
:ADSL MODEM/ROUTER/GW:
:eth0 Dynamic        :
:eth1 172.16.x.200   :
:--------------------:
       /\
       :
       :
     ISP "B"

=============================================

Network Diagram "B"

     ISP "A"                   ISP "B"
       :                          :
       :                          :
       :                          :
       \/                         \/
:-----------------:        :-----------------:
:LINUX ROUTER     :        :ADSL MODEM/ROUTER:
:eth0 202.x.x.1   :        :eth0 Dynamic     :
:eth1 172.16.x.100:        :eth1 172.16.x.200:
:-----------------:        :-----------------:
        :                           :
        :                           :
        :                           :
        -----------------------------
                     :
                     :
                     :
            :-----------------:
            :LINUX GATEWAY    :
            :eth0 172.16.x.1  :
            :-----------------:
                     :
                     :
                     :
              Client Computer's

Regards,
David Kandou

Re: iptables for backup connection

[Antony Stone]

On Monday 14 June 2004 10:56 am, david@suarapembaruan.co.id wrote:

> Dear all,
> In my office i using 2 connection (Wireless connection direct to ISP "A"
> and backup connection to ISP "B" with ADSL Modem), how to configure Linux
> iptables (gateway) so when connection to ISP "A" down client can still
> work with ISP "B" without reconfiguration at client computer.

This is not a firewalling question; this is a routing question.

The tool you need to set this up is iproute2.   See http://lartc.org for 
details.

Regards,

Antony.

-- 
Most people are aware that the Universe is big.

 - Paul Davies, Professor of Theoretical Physics

                                                     Please reply to the list;
                                                           please don't CC me.

Re: iptables for backup connection

[bino_oetomo]

----- Original Message -----
From: "Antony Stone" <Antony@Soft-Solutions.co.uk>
To: <netfilter@lists.netfilter.org>
Sent: Monday, June 14, 2004 3:05 PM
Subject: Re: iptables for backup connection


> On Monday 14 June 2004 10:56 am, david@suarapembaruan.co.id wrote:
>
> > Dear all,
> > In my office i using 2 connection (Wireless connection direct to ISP "A"
> > and backup connection to ISP "B" with ADSL Modem), how to configure
Linux
> > iptables (gateway) so when connection to ISP "A" down client can still
> > work with ISP "B" without reconfiguration at client computer.
>
> This is not a firewalling question; this is a routing question.
>
> The tool you need to set this up is iproute2.   See http://lartc.org for
> details.
>

Yup ...
iproute2 , for routing path definition
iptables , for NAT change
and BASH for connection testing and "puting it all together"

Sincerely
-bino-