On 2/4/2017 10:40 AM, otroan@xxxxxxxxxxxxx wrote: > Lars, > >>> My apologies: my comments were probably misleading. Certainly, this >>> document is simply RFC1981 to Std, and hence recommending RFC4821 would >>> be kind of ou of scope, here. >>> >>> That say, one might wonder to what extent, and for the general Internet, >>> RFC1981 can be considered succesful (given the filtering of ICMP >>> messages). -- i.e., at this point in time you wouldn't rely on RFC1981 >>> (icmp-based pmtud) for path-mtu discovery. >> What Fernando said: I'm certainly not opposed to lifting this to Standard, but it is painting an incorrect picture - PLPMTUD is de facto mandatory these days, and has been for years. > While I'm all in favour of PLMTUD. It doesn't seem like a complete solution. > PMTUD on the other hand supports all protocols on top of IP. If by "supports" you mean "doesn't work", then yes. That's why we now have PLPMTUD. > Looking just at our specifications, we cannot state that PLMTUD can replace PMTUD. Take RFC2473 (IPv6 tunnelling) for example. See draft-ietf-intarea-tunnels, esp. v03 Section 5.5.2 (yes, that doc has expired while we're preparing the 04 update, which should be issued shortly) Joe