You could make use of the fact that a bridge just forwards traffic without changing the MAC address, whereas a router decapsulates the packet from the Layer 2 header and re-encapsulates, using its own MAC address. Assuming you have a topology like this:
hosts-----2500e0------e04000-----hosts Do a show arp on the 2500 and 4000. In a routed network, you would just see the other router on the e0 interfaces. In a bridged network, you'll see the hosts' MAC addresses. Priscilla At 02:56 AM 3/19/02, dovelet wrote: >Hi all, > >Our company's network are connected using some Cisco 2500 and Cisco 4000 >routers. As we need to cater some non-routable protocols, bridging is also >enabled at all routers. I would like to know, is there any methods to >monitor which hosts are using bridging through the routers? Of course, I can >use a sniffer to capture the traffic, but the network is too large for us to >do so. > >Please advise. > >Regards, >Dovelet ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=38848&t=38758 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]