Hi,


I need a help in the following scenario:

We have leased line for connecting our head office with two different class of private network through a cisco router. This router ip has been configured as gateway for the users at ourside of the network. Now we have Email Server in our Head office which we connect through this router. We often encounter leased line disconnection and during this time i want to route through Internet. We have Linux as Squid proxy Server which i would like use it for firewall also. Hence, please let me know how i can configure firewall so that whenever leased line is down we can route through Internet. Ours is a class C network and Head is in Class B network.

Thanks in advance.

regards,

T. Saravana

hi tsaravan,

very simple,
just put another gateway on your client pointing to your linux firewall with the metric of 254 - which route will be triggered if your main gateway doesnt seem to be up - otherwise, it will be passive router. just do the same -- create NAT etc...

but - if that is not the case - just let us know.

HTH,

Cheers.

Hi ...
In the question of the firewall, you just have to configure Iptables in your linux machine (if you don't have it http://www.netfilter.org/projects/iptables/index.html , with that, the pc used as proxy cache, would work as a firewall too.
With that 2 programs, your network should work very fine.