Home Network with two routers

"That's possible, and I'd suggest DD-WRT/OpenWRT/X-WRT for the Linksys for extra configurability. I think you'll need it.

If the 2Wire is doing its DHCP properly, and serving out the x.x.2.x network, it doesn't really matter what IP the WAN interface of the Linksys gets -- unless you want the x.x.2.x machines to be able to talk to the x.x.1.x machines.

If that's the case, you'll need to see if the 2Wire will let you set a static IP -- maybe MAC-based via DHCP -- so the Linksys always gets the same IP on its WAN port (then you'll want it to be x.x.2.2). You'll also need to set host routes on the x.x.2.x machines to tell them that x.x.2.2 is the gateway for the x.x.1.0 network. (You may not need host routes if the 2Wire will let you configure a route so that it forwards packets to the x.x.1.0 network to x.x.2.2 -- then it does the internal routing for you.)

It's possible the 2Wire just isn't configurable enough to do what you want to do, though. In that case, there's another option.

Now with VLANs!

One more possibility you should consider is using your traditional WAN wiring (your first diagram, 2Wire -> Linksys -> devices/computers), but utilize VLANs in DD-WRT to do the network segmenting for you.

Go back to your original wire diagram, but this time configure VLAN1 to be (whatever port your switch is plugged into) and VLAN2 to be (other ports + wireless). DHCP requests on VLAN1 get one set of network settings -- x.x.2.x network, standard DNS settings, whatever; requests on VLAN2 get the other set -- x.x.1.x, OpenDNS filtering. The Linksys can do all the routing internally for cross-segment traffic, and naturally any internet-bound traffic gets routed out the WAN port.

This is a bit of a pain to set up, and some of it may not be supported by the configuration webGUI that DD-WRT/X-WRT offer, but it is all possible internally.

Edit: ""Internally"" means ""via the ssh interface"" -- ie, commandline control of DD-WRT."