It seems that some ISPs allow MTU 1500 over PPPoE (eg. BT with their FTTC links).
I tried to set it in the web interface (Shibby v100) but it takes it down back to 1492.
Does the RP-PPPoE that comes with Tomato allow MTU 1500? Can it be allowed in the configuration?
Ref: lists.roaringpenguin.com /pipermail/rp-pppoe/2011q2/000261.html