[149944] in North American Network Operators' Group
Re: Common operational misconceptions
daemon@ATHENA.MIT.EDU (Masataka Ohta)
Fri Feb 17 01:55:47 2012
Date: Fri, 17 Feb 2012 15:54:33 +0900
From: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
To: George Bonser <gbonser@seven.com>
In-Reply-To: <596B74B410EE6B4CA8A30C3AF1A155EA09CCF9BA@RWC-MBX1.corp.seven.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
George Bonser wrote:
> Modern (RFC 4821) PMTUD that is used by default by
> Solaris and Microsoft does not require ICMP and
> works well. For Linux you have to enable it:
It depends on how you define "work well".
As the RFC says:
indication of some significantly disruptive event in the network,
such as a router failure or a routing change to a path with a smaller
MTU.
it can not react against PMTU changes very well.
It is seemingly working well means there is not much PMTU
changes, which means we had better assumes some PMTU
(1280B, for example) and use it without PMTUD.
Masataka Ohta
