ic2: I'm not saying you are wrong, it just seems bloody odd to me that a very simple piece of functionaility would be left out of a router that is being sold to the general public.

I know the Linksys and the DLink act as switches rather than hubs so if it's sniffing the internal network you are trying to do forget it without putting a true hub between the network and the router. If it is actually preventing computer A from computer seeing computer B yet allowing both to access the WAN I would yell at them, return it and buy something that is of more use.....