On 2016-09-13, Harald Dunkel <harald.dun...@aixigo.de> wrote: > Hi Daniel, > > On 09/13/2016 12:00 PM, Daniel Gillen wrote: >> >> I had a similar problem. In my case it had to do with Path MTU issues. >> >> This site f.ex.: http://test-ipv6.com/ will check for that. >> >> The solution for me was to switch to "jumbo" frames below the pppoe >> device (1508 bytes if I remember correctly) and set the pppoe's MTU to 1500. >> >> Daniel >> > > I will surely try asap, but I wonder if this is allowed? > RFC 2516 says "... the PPP MTU MUST NOT be greater than > 1492". https://tools.ietf.org/html/rfc2516 > > ???
RFC 4638 supercedes this. Some providers + some xDSL bridges support it, some don't, you have to try it to find out. And you have to actively test rather than just see if it connects; not all ISPs have paths between LNS and LAC that can cope with baby jumbos - also sometimes it can fail if there are changes to the ISP's internal network or their L2/L3 providers.