Is it possible to run wireless router off of wireless Comcast modem?

[mebourbeau]

I have an office over my garage (detached from my house but only about 30-50 feet from modem in house).
The wireless signal is very weak. When I had the modem in the garage office, the wireless signal to the house was weak. Comcast thought their new wireless modem would address this, but it has not.

So, I have run a cat5 cable from the modem across the yard to the garage and hardwired it into a Linksis WRT54G Wireless Router.

Although I can connect to the router wirelessly, I cannot get internet access on my computer. I called Comcast, and they said they would have to disable the wireless signal from the modem if I want to activate the wireless router. I do not see how this will solve anything. They mentioned that to have 2 active wireless signals would create interference. Is this true? I can hardwire my computer to the router, but I also use a laptop and other wireless devices that I would really like to have a strong signal for.

Please advise.

 

[Cinders]

It should be possible without to much fuss.

I'd guess that you may have double WAN'd your network. The Comcast wireless device is determining what IP addresses all of your devices are supposed to get, and your WRT54G is probably doing the same thing. Both devices are probably set up to automatically provide DHCP services, and they are clashing with each other. The range of IP addresses for both devices may not even be the same. Since your WRT54G is an aftermarket device I'd disable DHCP on that machine (because it'll probably be easier to do and your Comcast device is closest in line to the modem because it is the modem, Oh and you'll have to log into your WRT54G's admin page to disable DHCP ) and make sure the line that runs from the Comcast device to the garage isn't plugged into the WAN port on your WRT54G router but is instead plugged into one of the four network/internet ports. The WAN port is the single port off to the left of the other four ports when viewed from the back.

It's possible with the right equipment to bridge two wireless routers and extend the range of your home network. A Linksis WRT54G firmware can be reflashed as a DD-WRT machine and bridged with another DD-WRT router. I know it's possible because I've done exactly that at my house.

You'll want to got to http://www.dd-wrt.com/site/index for any additional info on how to do that.