You bring up a good question. As far as I can see, your logic is correct, that any IP traffic destined for that "down" IP device should get sent out of the router to the destination MAC it shows in the ARP table, which in turn would get flooded out of all switches in the VLAN because none of them have a CAM entry for that MAC anymore.
I guess your best way to counter that would be to lower the ARP timeout on the router. Of course before I say that, I want to verify, which I did, and here's what I found: "With the default four hour ARP aging time, unicast flooding could occur for almost four hours. Reduce the ARP aging time on router interfaces to 5 minutes (using the arp timeout interface configuration command). This should significantly reduce the amount of unicast flooding without adversely affecting performance (the increased burden of ARPing placed on the router should not be significant in most cases). With a reduced ARP timer, unicast flooding should last 5 minutes at most." HTH, Mike W. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=37709&t=37609 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
