So I have my system running Fedora 15 and currently with a DSL line. The line provides a static IP along with static route, DNS. I run a web/E-Mail/DNS server from this IP. It also supports a NAT'd network to provide network and DHCP on the internal network.

I now would like to add another ISP which uses DHCP (Comcast) and switch the traffic generated from the NAT to go trough the new connection while maintaining the DSL connection for the server related functions. This will offload the traffic used by my family to the Comcast connection.

I'm trying to figure out the easiest way to do this with the Fedora configuration file however I'm not sure I can do this with the files alone. Most of the info I can find on the net has to deal with load balancing or fail over, neither are what I'm trying to achieve. The DHCP client for the Comcast connection also seems to through out using the standard Fedora config files as the routing gets set to the last interface brought up. I wish I could state that any routing for that interface go to a separate routing table and use that for the NAT.

Thanks for any info.

eth0 198.144.1.x DSL

eth1 192.168.0.x NAT

eth2 NOT USED (Broken)

eth3 x.x.x.x Cable (DHCP)

  • Why don't you just keep the networks separated? – Michael Hampton Dec 31 '12 at 3:33
  • @MichaelHampton How do you suggest that? With out providing separate hardware. – Ryan Dec 31 '12 at 3:43

What you need to do is policy based routing. I don't know if Fedora config files support this -- I'd say "no" if I had to guess...

Basically what you want to do is set up two different routing tables, one for external (routed) connections and leave the default routing table for local connections.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.