On Thu, Mar 15, 2001 at 08:06:59AM +0900, itojun@iijlab.net wrote:
> >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.

Ah, that was the problem.  I added "mtu 1500" to my boot script and rebooted
the router and now things appear to work.  Thanks for the hint!

But still, would it be so terrible to have a sysctl to enable fragmenting
even when DF is set? O:-)

  -jm