[Dnsmasq-discuss] seeing www.ietf.org fail dnssec with dnsmasq rc7

[Toke Høiland-Jørgensen]

Simon Kelley <simon at thekelleys.org.uk> writes:

> The MTU if the SIXXs IPv6 network interface is 1428. Failure to
> receive UDP packets larger than the MTU is a bigger bug than DNS, but
> I don't know if it's a SIXXS problem or a wider IPv6 one.

Well, IPv6 doesn't fragment packets; hosts are supposed to do PMTU
discovery and transmit at the MTU that works end-to-end. I've found this
to be broken way too often for comfort... Even encountered operators who
just told me to increase the MTU at my end rather than fix their
discovery mechanism (though this was when I was running with the minimum
1280 MTU and they were doing ethernet max-sized packets).

-Toke