>I tried "ifconfig gif0 mtu 1500" and, according to "ifconfig gif0", the
>new MTU value was set - but the router STILL reports it can't transmit
>the 1460 byte packets over the tunnel.  (Why doesn't the new MTU value
>work - or if gif can't use an MTU that high, then why doesn't ifconfig
>say so?)

	I guess you have a cloned routing entry which caches smaller path MTU
	value.  if so, remove the routing entry to refresh the path MTU value.
	if you don't have one, or if you still have problem after removing
	one, please let me know.

itojun