2 Routers, Cable Modem, Gigabit switch - HELP

I wired my house with cat5e. In my basement I have my cable modem attached to an AT&T "Plug&Share" Wireless G router.

From the AT&T Router out of a 100mbit port it then goes to a SMCGS5 5 port gigabit switch. The other 4 ports of the gigabit switch go to a couple of other computers.

One of the gigabit ports on the SMCGS5 goes upstairs into my office. I have an old Linksys BEFW11S4 wireless B router which I want to use as a router only in my office. In the linksys WAN port is the cable which is connected to the gigabit switch in the basement.

Attached to the Linksys router, in my office, is a Vonage phone, PC, Brother 420CN network printer.

cablemodem-->at&t wirelessg router-->smc gigabit switch-->linksys wirelessb router--->PC,Vonage & Printer

The AT&T router has DHCP active. The linksys is set to "router" on the "dynamic forwarding" tab (not gateway). DHCP on the linksys is disabled.

My linksys router is getting assigned an IP address (on the WAN port) from the AT&T router. I want the devices attached to the linksys router to also get it's DHCP addresses from the AT&T router as I want the AT&T router to be the only DHCP server. I cannot get any of the office devices to obtain an IP address from the AT&T router. "ipconfig /renew" times out.

The only way I can get it to work is to enable DHCP on the linksys and have 2 dhcp servers. The AT&T providing 192.168.0.0 addresses to it's attached devices and the Linksys router providing 192.168.1.0 addresses to the upstairs devices. When I do that it works but the upstairs linksys router is getting assigned it's IP address from the AT&T router. So my linksys has 2 addresses. The default 192.168.1.1 address it provides for itself and the 192.168.0.103 address the AT&T router is assigning to it's WAN port.

This is also a problem for any computer attached to the AT&T/gigabit switch because the linksys router treats everyting connected via the WAN port as external and does not allow communication from the AT&T side into the linksys side of my office.

Please help. I want the AT&T router to be my DHCP server and my linksys wireless router to be just a router.

What am I doing wrong? Thanks!

BTW- everyting is hard wired cat5e

 

You have to hook the network to the LAN port, not the WAN port if wanting to use the Linky as a Wireless Extender. Then from there it should work. And what I would do is hook the Vonage to the Router, and run another line for the Other.

 

I tried that. I don't want to use the linksys as a wireless extender. The wireless feature of the linksys is disabled. All I really want is to make use of the additional ports on the back of the linksys so I have more connections in my office (without having to run multiple cables up from the basement). When I connect the gigabit connection to the LAN port I cannot get a connection.

With DHCP turned off on the linksys should the ATT router be able to provide DHCP addresses through the linksys?

Thanks for you help.

 

Not if you are hooked up to the WAN port, due to the router will still act as a router, and not a switch. I would go out and purchase a switch, due to they are not that much anymore.