MTU mismatch on one link

Paul Vinciguerra pvinci at VinciConsulting.com
Fri Aug 31 08:52:09 CDT 2012


You need to raise your MTU above that on the other side and do a ping size sweep.  Unlike at Layer-3 when you can use set a DF bit and get back an ICMP error, at Layer-2 when you exceed the far side's MTU, the packets are silently dropped.


Paul Vinciguerra
CCIE# 10291

120 W Park Avenue, Suite 308
Long Beach, NY 11561
P: 516-977-2095  .  F: 516-977-2482  .  TF: 866-998-4624
vinciconsulting.com



-----Original Message-----
From: Tom Taylor [mailto:tom.taylor.stds at gmail.com] 
Sent: Friday, August 31, 2012 9:30 AM
To: NANOG list
Subject: MTU mismatch on one link

Has anyone run into a situation where the MTU at one end of a link was configured differently from the MTU at the other end? How did you catch it?

In general, do you see any need for a debugging tool to be standardized to find such mismatches?

Tom Taylor




More information about the NANOG mailing list