Hi to hall,
i have a big network where the clients are connected only with rb133c and only in PPPoE mode.
i have a problem with the MRU and MTU parameter, if i set 1500 on pppoe server and 1500 on client, any client do not go in internet or only in any site.
My question is, wich is the correct paremeter of mru and mtu with pppoe server (rb500) and on client side with rb133c??
thx
ElDiablo -From Litfiba-
MTU MRU 1480 because of encapsulation of pppoe 
http://www.mikrotik.com/testdocs/ros/2.9/interface/pppoe.php ← troubleshoting
MTU MRU 1480 at server and client, right?
Thx
Leave it to its default, PPPoE has 20 bytes overhead that’s why it decreases MTU at 1480 bytes. If you have something else configured in your network like tunnels ect or by any chance facing MTU trouble, try adjusting it in the mangle.
Regards
Faton
my dafault value, when i make a server PPPoE is 1500, but this is wrogn.
i change the value at 1480 and try it.
Regards
ElDiablo
I’m very surprised, when you create an pppoe server in mikrotik automatically will set the max MTU and max MRU at 1488