[29322] in North American Network Operators' Group
Re: PMTU-D: remember, your load balancer is broken
daemon@ATHENA.MIT.EDU (Paul Vixie)
Sat Jun 17 15:02:45 2000
To: nanog@merit.edu
From: Paul Vixie <vixie@mibh.net>
Date: 17 Jun 2000 11:59:30 -0700
In-Reply-To: Valdis.Kletnieks@vt.edu's message of "14 Jun 2000 08:11:30 -0700"
Message-ID: <g3aegkxhf1.fsf@redpaul.mibh.net>
Errors-To: owner-nanog-outgoing@merit.edu
Valdis.Kletnieks@vt.edu writes:
> Has this changed? Has "fragmentation" become a Great Evil, ... ?
Yes. http://research.compaq.com/wrl/techreports/abstracts/87.3.html says:
Research Report 87/3, December 1987
87.3 -- Fragmentation Considered Harmful
Christopher A. Kent, Jeffrey C. Mogul
PostScript Version
gzipped PostScript Version
Adobe Acrobat PDF Version
Internetworks can be built from many
different kinds of networks, with varying
limits on maximum packet size. Throughput is
usually maximized when the largest possible
packet is sent; unfortunately, some routes
can carry only very small packets. The IP
protocol allows a gateway to fragment a
packet if it is too large to be transmitted.
Fragmentation is at best a necessary evil; it
can lead to poor performance or complete
communication failure. There are a variety of
ways to reduce the likelihood of
fragmentation; some can be incorporated into
existing IP implementations without changes
in protocol specifications. Others require
new protocols, or modifications to existing
protocols.
wrl-techops@pa.dec.com
Copyright © 2000 Compaq Computer Corporation
I was there, I saw the research that went into this, I know the guys who
did the work, and I agree completely with the conclusions thus presented.
