Thoughts on increasing MTUs on the internet

Thu Apr 12 11:03:45 UTC 2007

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.