Any reason the CHR wouldn’t be able to run a 1500byte PPP MTU providing the physical interface is at least 1508 Bytes as is the Vswitch.etc?
Mine connects at 1500 and then drops to 1480 for some reason.
Had 1500Byte MTU working on the pfSense firewall that I was using previously.
The behaviour of dropping MTU from 1500 to 1480 seems to be related to the Mikrotik sending a large LCP Echo packet and not getting a (valid) reply (see my posts here - http://forum.mikrotik.com/t/pppoe-and-mtu-1488/101793/1).
Interesting thanks,
Might have to take a packet capture and then see if the ISP (Or something in the middle) isn’t responding correctly.
I tried setting the MTU at 1500 from the ISP end as well but no dice (Yes they actually expose that in their control panel!)