References: <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> Subject: Re: Spurious MTU in IPv6 RAs Where WAN is PPPoE In-reply-to: Your message of "Mon, 11 Jul 2011 00:20:03 +0900." <[email protected]> -------- In message <[email protected]>, Masataka Ohta writes: > Iljitsch van Beijnum wrote: > > > But with IPv6 we have a new chance to punish the people creating > > the problem rather than the ones implementing PMTUD properly, > > so The Right Thing To Do is NOT fix any PMTUD breakage in > > properly behaving systems, but rather push people that > > configure their systems incorrectly to fix this. > > Let's see the reality. > > IPv6 is broken to request packet too big ICMPs must be > generated even against multicast packets, which causes > serious periodic ICMP implosions when MTUs are, because of > tunneling, below 1500 near many receivers and is 1500 at a > sender and other part of the network. > > It means that rational operators MUST filter some ICMP > and, not surprisingly, some operators will block all > ICMP or all packet too big ICMPs, which means PMTUD > won't work. > > Who are the people to be punished for creating the problem? > > Masataka Ohta > _______________________________________________ > Ietf mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/ietf Which only happens if applications disable IPV6_USE_MIN_MTU for multicast packets (the default is to fragment multicast packets at network MTU (1280)). So to get this you need a broken stack or a brain dead application. Mark -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: [email protected] _______________________________________________ Ietf mailing list [email protected] https://www.ietf.org/mailman/listinfo/ietf
