Hello. I'm a network illiterate trying to create a home network with a design like the one in the image. And when I say Home I mean also cheap. Cisco might be the perfect solution for network connectivity and world peace, but I can't afford it. As I can't post images, please copy&paste ... h**p://i37.tinypic.com/33cuiys.jpg A, B : RouterB is connected to DSL. Both have wifi enabled and are connected to each other by Ethernet. #1, #2 : Two PCs, #1 connects via wifi and #2 uses Ethernet. #1 can only use DHCP. #3, #4 : Two PCs, #4 connects via wifi and #3 uses Ethernet. My main problem is that the Green group must work always. Group B can go offline at any given time, but #1 must reliably send data to #2 ALWAYS. I can do that just running this Green group isolated from the Red one ... but that means without internet. The problem comes when I try to make the Green group have internet access : If I have to disable DHCP in routerA to let RouterB manage that and be able to get internet connection ... and the routerB goes suddenly offline ... then #1 and #2 can't connect, and I can't let that happen. So ... the way I see it, both groups have to work as independent networks except that Green group must acquire internet connection via RouterB somehow. It would be nice if #1, #2, #3 and #4 could share data, but I'm willing to sacrifice that in order to get a reliable #1 to #2 connection. Well, thats all. That's my question : how do I make it work ?
What about DHCP reservation, all computers will have a set IP address via matching the MAC address to the reservation table created in the router. You just log into the router (you have not stated make or models here...) and look for like LAN setup and address reservation (used my router as example, Netgear DGN2000). It will list current connected clients, you select one, click add reservation and put in an IP you want to have that specific device on. Do for each client, ensuring that no IP's are the same for 2 different clients!