North American Network Operators Group
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Re: MTU (was Re: ULA and RIR cost-recovery)

  • From: Bill Owens
  • Date: Thu Nov 25 09:12:00 2004 
On Thu, Nov 25, 2004 at 02:05:25PM +0000, Alex Bligh wrote:
> Given how pMTUd works, this speculation should be relatively easy to test
> (take end point on >1500 byte MTU, run traceroute with appropriate MTU to
> various points and see where fragmentation required comes back). Of course
> I'd have tried this myself before posting, except, urm, I can't find a
> single machine I have root on that I can get more than a hop or two from
> without running into 1500 byte (or less) MTU.

I happen to have such a machine and an application that specifically tests hop-by-hop MTUs, if there are any specific destinations you'd like checked. It has 9k to the R&E world, and 4470 to Qwest.

Bill.