On 19.01.2015 18:42, Brielle Bruns wrote: > On 1/19/15 5:52 AM, Artem Viklenko wrote: >> 19.01.2015 13:12, Mikael Abrahamsson написав(ла): >>> On Mon, 19 Jan 2015, Ignatios Souvatzis wrote: >>> >>>> I had some problems at home, which is not tunneled, but a >>>> less-than-1500-octet-mtu PPPoE DSL line, so - thinking it's tunnels >>>> only ignores an increasing number of native private users. >>> >>> Well, PPPoE is a tunnel, but I guess that's splitting hairs. >>> >>> But regardless, I had trouble this morning with Youtube that might be >>> related to the same issue. >>> >> >> >> One possible solution to force TCP MSS. For example on my FreeBSD >> router at home i used PF's scrub rule for ipv6 tunnel to set >> mss to 1220 bytes. >> >> If you use PPPoE as underlying technology, decrease this vale little >> bit more - 1212 or less. >> >> >> > > Min MTU size allowable for ipv6 is 1280 according to RFC. Wouldn't > setting the MSS size to 1212 or 1220 essentially break that RFC as well > (1220+40 < 1280) or does the RFC only explicitly state the MTU has to be > at least 1280? > >
I'm not shure about RFC right now. But spending time trying to fugure out why one or the other host can't be successfully reached using ipv6 finnally I stopped on this value. It may be not optimal, but it works for me. And indeed the main cause of this is the blocking ICPMv6 at the far end. -- Sincerely yours, Artem Viklenko.
