Originally posted here by Tiger Shark
Actually the BEFSR41 will not allow a sniffer to work properly since it is a switch in itself. However if you pop a cheap hub on a single cable between all your PC's and the router it will broadcast all the traffic to you.

I don't know about other Cable/DSL routers but I suspect they would be the same.

Yea, but couldn't you use Ettercap to sniff the switched network?