With baby jumbo PPPoE support, the VDSL side of the 130 modem has an MTU of 1508. I have a need for an MTU of 1516 (my ISP runs PPPoE over a VLAN inside the VDSL VLAN), and apparently BT supports MTUs around 1530. I'm terminating the PPPoE at an external device, having untagged the bearer VLAN at my switch. This set up works with the standard ECI BT supplied modem, but the line has been unstable, hence moving to the 130.

My efforts so far indicate an established MTU of 1500 along the PPPoE tunnel, but ping fragmentation tests show an MTU of 1492, which indicates to my basic network knowledge that the MTU on the VDSL or LAN side is limited to 1508.

My question is, can I set an MTU >1508 on the VDSL interface. CLI commands are fine with me

To post to myself - SIN 498 shows the maximum MTU (frame size) on R.ETH.1 is 1534. So assuming that the 130 is SIN 498 compliant, it should support the higher MTU on the interface. I'll do some more digging, but any help is appreciated

I know the 2860 doesn't, I've complained to support about this before.