IPv6 MTU discrovery -- how should it work?

Lev Serebryakov lev at FreeBSD.org
Sun Apr 29 16:02:51 UTC 2012

Hello, Lev.
You wrote 29 апреля 2012 г., 18:47:52:

LS>>   When I connect to external server twice, and run tcpdump in one
LS>> session for another one, and then try to use second (sniffed) session
LS>> for bulk transfer, I can clearly see, that server tries to send IPv6
LS>> packets with size 1420 to my local  network  many  times  and  doesn't
LS>> get any answer, so it is MTU problem for sure, but how it could be fixed?
  And  I can not set mtu less than 1280 on gif0, and my IPv4 interface
only  have  1460, as it is PPPoE interface. Maybe, problem is here, as
MTU 1280 assumes outer MTU is 1500?

// Black Lion AKA Lev Serebryakov <lev at FreeBSD.org>

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