Toerless Eckert wrote: > Not sure why rfc1981 PMTUD was never fixed. Because IPv6 people believe multicast PMTUD MUST work. RFC1981 even states: The local representation of the "path" to a multicast destination must in fact represent a potentially large set of paths. that they actively bless multicast PMTUD to cause implosions. > We did manage to get section 11.1 into rfc 3542 though. It's a little > bit long due to committee design, but i was hoping it was sufficient to avoid > the problem by default. It is not a protection against malicious attempts nor decided attempts by PMTUD believers-in, which means cautious operators must still filter ICMPv6. Considering that destination address fields of inner packets in ICMPv6 are located at the 73th to 88th bytes (ignoring MAC header), which may not be filtered by hardware, it is likely ICMPv6 packet too big against unicast packets will also be filtered. > If folks see IPv6 multicast> 1280 as a > real problem in deployments, It is merely that IPv6, as is, is not operational and operators MUST violate RFC2463 not to generate ICMPv6 packet too big and filter ICMPv6 packet too big. It, of course, is a real problem against PMTUD, including unicast ones. Masataka Ohta _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf