My apologies for not reading your post carefully.
I see an MTU of 1280 to www.python.org at my end - ipv6 tun device on my
router is set to this, so I think it can deal with the 1500 MTU on my
local machine's interface. Nice spotting :)
Regards,
Tom
gummay ~ # tracepath6 www.python.org
1?: [LOCALHOST] pmtu 1500
1: 2001:44b8:62:120::1 0.695ms
1: 2001:44b8:62:120::1 0.630ms
2: 2001:44b8:62:120::1 0.691ms pmtu 1280
*snip*
24: dinsdale.python.org 460.627ms reached
Resume: pmtu 1280 hops 24 back 51
Lindsay Haisley wrote:
On Sat, 2009-05-16 at 13:07 +1000, Tom Fifield wrote:
I have encountered this problem before, however www.python.org works
fine on ipv6 for me. Many cases where things fail is because DNS
resolves the AAAA record, but the ISP/upstream providers don't have IPv6
connectivity to the site.
I'm using a v6->v4 tunnel broker so my ISP is out the loop, what's more,
as I said,
www.python.org also
resolves with an aaaa record (2001:888:2000:d::a2), and I can ping6
the server, so I know that routing is OK.
It looks as if the problem may be related to MTUs. I did a bit of
jiggery-pokery with MTUs, setting the MTU for the IF on my desktop
system slightly lower than the MTU on the LAN IF of my router, and it
appears that the problem is solved for now, at least.
I've seen network problems before with MTU issues, especially where UDP
packets are involved, as they may be with the tunnel broker.
