I have a D-Link DIR-655 wireless rounter in the basement and want to use a Linksys BEFW 11S4 wireless router as an access point upstairs, to extend the range. I read a post that said I should connect the ethernet cable from the D-Link (downstairs - main network) to the LAN port of the Linksys (upstairs) and then run an ethernet cable from the Linksys LAN port to the computer upstairs. It also said I should use the same SSID as the D-Link, disable the DHCP on the Linksys and change the channel so that it isn't the same as the D-Link, which I did.
The problem (one of them) is that if I plug the D-link into the WAN port I can still see the D-Link router admin page from the computer upstairs (connected to the Linksys) but if I switch the cable to a LAN port on the Linksys, I can't see the D-Link any more. Neither confguration will allow me to see the D-Link main network downstairs through the Linksys router.
The password on the D-Link is a alpha-numeric word which all my devices are set-up for, but the Linksys seems to force a computer generated alpha-numeric code based on the same password. Do I have to use the linksys code for the D-Link and all devices?
They all actually use that passkey to generate the security code.
Leave the link LAN to LAN port and do the final step that it sounds like you missed: give the AP a static IP address in both the AP and in the router -- make it in the router range but outside of the DHCP range, so if your router is 192.168.1.1, make the AP 192.168.1.2, and start the DHCP range in the router at 192.168.1.3.
If you ever need to get back into the AP to configure it more, just attach by wire and use the new static address to get to its configuration pages.