IPv6 day and tunnels

Joe Maimon jmaimon at ttec.com
Sun Jun 3 20:38:58 CDT 2012

Well, IPv6 day isnt here yet, and my first casualty is the browser on 
the wife's machine, firefox now configured to not query AAAA.

Now www.facebook.com loads again.

Looks like a tunnel mtu issue. I have not as of yet traced the 
definitive culprit, who is (not) sending ICMP too big, who is (not) 
receiving them, etc.

www.arin.net works and worked for years. www.facebook.com stopped June 1.

So IPv6 fixes the fragmentation and MTU issues of IPv4 by how exactly?

Or was the fix incorporating the breakage into the basic design?

In IPv4 I can make tunneling just work nearly all of the time. So I have 
to munge a tcp mss header, or clear a df-bit, or fragment the 
encapsulated packet when all else fails, but at least the tools are 
there. And on the host, /proc/sys/net

In IPv6, it seems my options are a total throwback, with the best one 
turning the sucker off. Nobody (on that station) needs it anyways.


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