After spending Sunday afternoon setting up a wireless access point I decided to resurrect my wired router (Linksys BEFSR41) and connect it to my wireless router (Linksys WRT54G). I used up all my ports on the wireless router and didn’t want to buy a hub. I tried a few months ago to get the wired router to work but to no avail. Turns out I was plugging the WAN port from the wired router to a numbered port on the wireless router. This works but creates two different networks. I wanted a single network.
The solution was to connect a numbered port from the wired router to a numbered port on the wireless router. You also need to disable DHCP on the wired router. That’s it. It works great, I now have 3 free ports.