Can you explain the configuration of the WRT54G so that it can attach to the VIP1200? Is it just a matter of letting the 2wire handle DHCP and turning off DHCP on the WRT54G?
I mainly wanted the Linksys up there to make the wireless coverage better. If you are just looking to add wired items on through it, you are close to correct.
1) You disable the DHCP on the Linksys
2) Give it a permanent IP address that is within the 2Wire's range (I made mine 192.168.100.253)
3) Disable the firewall (the 2wire firewall has you covered) NOTE that I did not disable my Wireless security settings.
4) Plug the cat 5 from the 2wire into one of the Ethernet ports (not the WAN port).
5) The Linksys essentially becomes a switch with 3 ports you can use for other devices.
6) Connect the Linksys and the VIP1200 with a Cat5 patch cord.
If you want to extend your wireless network, you need to to steps 1-4 above, PLUS
1) Give your Linksys SSID the same name as your 2wire (or whatever name you want for BOTH) so you only have one SSID.
2) Change the channels for your wireless devices to be as far apart as possible (my Linksys is on channel 11 and my 2wire is on channel 1)
3) Ensure that your security settings for the wireless networks are the same. Will fill in this detail about what I set it to when I get home tonight.
My Linksys wireless security is set for WPA2 Personal Security Mode, with AES encryption. I had it set initially to TKIP+AES but then realized that the 2wire could only do AES and they have to be the same otherwise you get issues. The 2wire is set for WPA2-PSK (which is the same as Personal on the Linksys). You have to select the Custom Pass Phrase on the 2wire so you can match it as the same one that you are using on the Linksys for your WPA Shared Key.