1492 or 1480 or 1460?
THX
What is your L2MTU of all interfaces in the network?? if 1500, then 1492 for default pppoe usage. but I suggest to use 1480 
1492 or 1480 or 1460?
THX
What is your L2MTU of all interfaces in the network?? if 1500, then 1492 for default pppoe usage. but I suggest to use 1480