On 6/3/19 01:09, Mark Andrews wrote: > > >> On 6 Mar 2019, at 1:30 pm, Fernando Gont <[email protected]> wrote: >> >> On 3/3/19 18:04, Mark Andrews wrote: >>> There are lots of IDIOTS out there that BLOCK ALL ICMP. That blocks PTB >>> getting >>> back to the TCP servers. There are also IDIOTS that deploy load balancers >>> that >>> DO NOT LOOK INSIDE ICMP messages for redirecting ICMP messages to the >>> correct >>> back end. There are also IDOITS that rate limit PTB generation to >>> ridiculously >>> low rates. One should be able to generate PTB at line rate. >>> >>> Everyone that has configured mss-fix-up has contributed to misunderstanding >>> that >>> you can block ICMP. It is time we had a flag day to REMOVE mss-fix-up from >>> all >>> the boxes you control. We need to get PTB working and unfortunately that >>> means >>> that we need to stop pandering to admins who don’t know how IP is supposed >>> to >>> work. ICMP is NOT optional. >> >> It would seem IETF's intention is to actually move away from >> ICMPv6-based PMTUD, to the extent that is possible. (RFC4821). > > Which is not a reason to not fix broken equipment and misconfigured firewalls. > The workarounds are basically there because people deploy broken equipment.
Agreed. That said, it wasn't solved in 30+ years of IPv4. Do you have hopes it will be different with IPv6? Thanks, -- Fernando Gont SI6 Networks e-mail: [email protected] PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492
