How to force "Actual MTU" on PPPoE client

[himurae]

It’s very frustrating that this issue is ignored my Mikrotik.

It used to work a few year ago.

I showed them evidence that using different hardware, i got an mtu of 1492 with no issues, confirmed with pinging with a packet size of 1464 (1464+28=1492).

Everything remaining the same, when I used a mikrotik router (I have several), the mtu dropped to 1480.

So, it is very obvious that my ISP supports mtu of 1492 with pppoe.

I raised a support ticket.

Basically, they said

1. Must be some hardware between me and my ISP.
   If that was the case, how come using other routers I managed to get mtu of 1492 and with actualy pings proving it was mtu 1492?

2. Then they said, since it was written in their wiki that mtu of 1492 was supported, that means there was no issue???!!!

Then they closed the ticket.

I took time to explain the situation with screenshots of the ping resutls of other routers as compared to miktorik.

Looks like they didn’t bother to read through it

This issue is most definitely NOT solved

I have exactly the same issue and my isp supports RFC 4638 all other routing softwares like opnsense/vyos give me 1492 but mk sticks to 1488

http://forum.mikrotik.com/t/pppoe-mtu-always-defaults-to-1480-instead-of-1492/181991/1