IPv6 day and tunnels

bmanning at vacation.karoshi.com bmanning at vacation.karoshi.com
Mon Jun 4 03:26:20 UTC 2012


On Sun, Jun 03, 2012 at 10:05:40PM -0400, Joe Maimon wrote:
> 
> 
> Joe Maimon wrote:
> 
> >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.
> >
> 
> The culprit is the v6 tunnel, which wanders into v4 ipsec/gre tunnels, 
> which means the best fix is ipv6 mtu 1280 on the tunnels, and possibly 
> on the hosts. PMTUD works fine, just comes up with the wrong answer.
> 
> 1280, the new 1500.
> 
> 
> >Joe


	actually, to be safe,   1220.


/bill




More information about the NANOG mailing list