Hoi, 2014-11-11 11:13 GMT-08:00 Jeroen Massar <[email protected]>: > As stated, the MSS clamping is just hiding the real problems. It does > not properly resolve anything. You are simply wrong about this statement. MSS clamping effectively resolves issues with PMTUD by reducing its necessity in the first place. I think I'm the ninth person to point that out in this thread?
The reason why operators resort to MSS clamping, is because they then take end to end delivery reliability into their own hands, and have more control over the flow of their data onto the internet. The "real problems" you bring up, are almost impossible to address without explicit cooperation from all affected parties - this is a method that does not scale, and is not considered a winning strategy by operators who wish to actually see their packets reach the intended recipient. > If I had not commented about this problem, > it would never have come to light... maybe in several years when nothing > could have been done anymore. But today, we still can fix things. While it's great that you noticed it, I think it's mendacious to claim that if you had not commented on the problem, it would not have come to light. Also, I'd like you to keep in mind that there can be some significant wall clock time between noticing a problem and completing its resolution, in a network or server deployment of sufficient size this can take a while. So saying "they just did not notice it this time around and thus it took a while for them to wake up (timezones :) figure out what it is and fix the issue" carries little merit if you don't actually know what happened, how it got noticed, or how it got resolved. > Noting problems and properly fixing them are important. but but but ... the problem *was* fixed, and whether you like it or not, it was fixed by restoring the intended behavior of MSS clamping in the affected Google servers after they had a regression. It's fine if you want to practice pedantry, and I applaud your persistence. But you must understand that ipv6-ops being network engineers by trade will in general resort to "doing that, which actually gets the job done". groet, Pim -- Pim van Pelt <[email protected]> PBVP1-RIPE - http://www.ipng.nl/
