As you can see, I have two routers 1) an Edimax BR-6624 Dual WAN router where ISP1 goes to and a 2) Linksys WRT300N where ISP2 goes. The Windows XP PC connects to both and now it is multihomed. I have configured the PC to use the Linksys router as default gateway so my browsing and downloads goes through ISP2 and my services will listen on the connection from the DUAL WAN router.

Another thing to notice is that the Dual WAN router has its failover connection from the Linksys router which is effectively ISP2. So if ISP1 fails the other PC connected to the Dual WAN router will connect through ISP2.

There is only a tricky problem which I am not able to resolve until this time. I want my HTTP and FTP services available to the internet via ISP1 which have the static IP. I have configured port forwarding for this services to the Windows XP PC. Oddly enough it is not working, and I am clueless.

I have as well tried NAT aliasing which does not work, DMZ which as well does not work. So I am wondering if the WIndows XP PC is the point of failure. I haven’t got enough help to resolve this however I will keep looking and will update this post.