[95954] in North American Network Operators' Group
Re: Thoughts on increasing MTUs on the internet
daemon@ATHENA.MIT.EDU (Iljitsch van Beijnum)
Thu Apr 12 07:04:47 2007
In-Reply-To: <87r6qpykou.fsf@clarabella.noc.seabone.net>
Cc: NANOG list <nanog@merit.edu>
From: Iljitsch van Beijnum <iljitsch@muada.com>
Date: Thu, 12 Apr 2007 13:03:45 +0200
To: Pierfrancesco Caci <p.caci@seabone.net>
Errors-To: owner-nanog@merit.edu
On 12-apr-2007, at 12:02, Pierfrancesco Caci wrote:
> wouldn't that work only if the switch in the middle of your neat
> office lan is a real switch (i.e. not flooding oversize packets to
> hosts that can't handle them, possibly crashing their NIC drivers) and
> it's itself capable of larger MTUs?
Well, yes, being compatible with stuff that doesn't support larger
packets pretty much goes without saying. I don't think there is any
need to worry about crashing drivers, packets that are longer than
they should are a common error condition that drivers are supposed to
handle without incident. (They often keep a "giant" count.)
A more common problem would be two hosts that support jumboframes
with a switch in the middle that doesn't. So it's necessary to test
for this and avoid excessive numbers or large packets when something
in the middle doesn't support them.
