Subject: Re: Path MTU discovery
To: None <tech-net@NetBSD.ORG>
From: Wolfgang Rupprecht <>
List: tech-net
Date: 07/15/1997 12:20:47
mo@UU.NET (Mike O'Dell) writes:
> but if you put an FDDI interface into your box and have
> it talk to another server, how will your hard-wired MTU of 1460
> take advantage of half as many packets per NFS transfer??

Under NetBSD the MTU is specifiable on a per-routing table entry
basis.  If I had an FDDI I'd simply allocate a network for the FDDI
and set that MTU to 4k (or whatever the exact number is).  Adding the
following to the rc file, sure is faster than adding the MTU-discovery
code to the kernel.

	route add  -mtu 4096 -net x.x.x.0 myinterface

Wolfgang Rupprecht    <>