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Re: PMTU-D: remember, your load balancer is broken

  • From: Paul Vixie
  • Date: Sat Jun 17 15:04:28 2000

[email protected] writes:

> Has this changed?  Has "fragmentation" become a Great Evil, ... ?

Yes. says:

                              Research Report 87/3, December 1987 

                              87.3 -- Fragmentation Considered Harmful 

                              Christopher A. Kent, Jeffrey C. Mogul 

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                              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

                              [email protected]
                              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.