Re: FW: New Version Notification for draft-bonica-6man-frag-deprecate-00.txt

[Hagen Paul Pfeifer <[e-mail]>]

* Ronald Bonica | 2013-06-21 19:00:51 [+0000]:

>I don't know of a study. However, this is probably a safe assumption considering that:
>
>- many TCP implementation leverage PMTUD
>- many enterprise block fragments
>- many firewalls, by default, block IPv6 fragments

One of my clients using extensive fragmentation features, their
application/transport layer is "build around" IPv6 fragmentation. Problem:
all components are hard wired in silicon, there is no change/modification
possible in the next decade.

I'm a little bit sad about this incompatible protocol change/break.
Fragmentation was an early design failure in IPv4 - for IPv6 fragmentation it
is still supported and I see no way to obsolete fragmentation without
incompatible protocol change. Especially "New IPv6 host implementations MAY
support IPv6 fragmentation and reassembly, but are not required to do so." and
"Network operators MAY filter IPv6 fragments.". - this break legacy
application/stacks using fragmentation.

Fragmentation is a nightmare for a middleboxes, no doubt and fragmentation was
an design failure. But fixing it in a incompatible manner is even worse. There
should never ever an protocol break.


Hagen