Date: Sun, 29 Apr 2012 18:35:59 +0400 From: Lev Serebryakov <lev@FreeBSD.org> To: freebsd-net@freebsd.org Subject: IPv6 MTU discrovery -- how should it work? Message-ID: <75233009.20120429183559@serebryakov.spb.ru>
next in thread | raw e-mail | index | archive | help
Hello, Freebsd-net. My home network is connected to IPv6 world with Hurricane Electric's tunnel (IPv6 over IPv6, "gif"). It has MTU 1280. Everything works till packets are small -- for example, interactive shell (ssh) session over IPv6 works great. But when I need to transfer buil of bytes from server to local network (scp, or even fast scrolling of man page in interactive session) traffic hangs. It starts to work after couple (5-10) minutes, but many applications has timeouts less, that that, and it is very annoying in any case. When I connect to external server twice, and run tcpdump in one session for another one, and then try to use second (sniffed) session for bulk transfer, I can clearly see, that server tries to send IPv6 packets with size 1420 to my local network many times and doesn't get any answer, so it is MTU problem for sure, but how it could be fixed? Also, Youtube doesn't work over IPv6 with same symptoms, so it is not only my servers' problem, it looks like my local network (and tunnel) problem. How should it work? Maybe, I'm filtering out something mandatory on firewall? -- // Black Lion AKA Lev Serebryakov <lev@FreeBSD.org>
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?75233009.20120429183559>