Re: IPv6 connectivy problems, with tcpdump

[Takahiro HAYASHI <t-hash%abox3.so-net.ne.jp@localhost>]

Hello,
If there are Path MTU discovery blackhole router(s) between web server
and your client, such packets can be seen; server does not send
large packets but does small ones and client replies ack with SACK.


On Thu, 10 Oct 2013 14:10:13 +0200
Reinoud Zandijk <reinoud%NetBSD.org@localhost> wrote:

> Hi folks,
> 
> i'm experiencing some odd problems with my IPv6 provider. Sometimes all works
> fine but at other times just opening a connection or getting a webpage just
> fails without a clear reason to me or a ftp transfer just halts in the middle
> and never revives.
> 
> I've created a tcpdump of Firefox on NetBSD/i386 of loading a webpage from
> some IPv6 enabled website. I've seen similar behaviour on NetBSD/amd64 and
> even on Windows7, so i dont think its NetBSD related. For privacy reasons i've
> replaced some of the actual addresses since this is going for public.
> 
> Could you please take a look at the trace and/or give me some pointers as how
> to debug this? Is this a problem at my ISP provided modem? Or is it upstream
> my ISP ?
> 
> The tcpdump is at: http://pastebin.com/3MPg6qnE
> 
> With regards,
> Reinoud Zandijk
> 

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t-hash