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)