Comment by izacus
1 day ago
The MTU thing is a bit bizarre - all connections I've seen on PPPoE in practice (fiber or DSL) used 1492 MTU to fit data into frames (and ISPs configured their routers like that too). What are you trying to hack with this unusual 1508 frame size?
It's not a hack. It's literally having the tunnel at 1500 MTU.
Check my answer to the sibling comment [0]. It's also known as mini jumbo frames, and is documented in RFC4638 [1]. And here's a post [2] talking about using it on OpenReach FTTC, which is similar to my own infrastructure, only I'm FTTP.
[0] https://blah.cloud/networks/enabling-mini-jumbo-frames-rfc46...