Default MTU values

Table: MTU default values shows the default MTU values which are dependent upon the (sub-) port type, mode, and encapsulation.

Table: MTU default values
Port type Mode Encap type Default (bytes)

Ethernet

access

null

1514

Ethernet

access

dot1q

1518

Fast Ethernet

network

—

1514

Other Ethernet

network

—

 92121
Parent topic: MTU configuration guidelines
1 The default MTU for Ethernet ports other than Fast Ethernet is actually the lesser of 9212 and any MTU limitations imposed by hardware which is typically 16K.