On 2012-03-25, at 3:34 PM, Randy wrote: > ...so a "sh ip int vlan x" says ip mtu 1998? > I can understand "sh int vlan x" would reflect the system mtu. > ./Randy Indeed. show ip int does indeed inherit the routed MTU. So one other riddle - when I set the MTU of the ES port to 1600, the ISIS adjacency stays up. Shouldn't that get torn down?