IPv6 MTU discrovery -- how should it work?

[Lev Serebryakov]

Hello, Lev.
You wrote 29 апреля 2012 г., 18:35:59:

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?
 But

server# ping6 -D -s 1420 <host-after-tunnel-with-mtu-1280>

 Works!

 I don't understand, what happens here :(

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