ip mtu

Sets the maximum transmission unit (MTU) size for the interface.

ip mtu <bytes>
 
no ip mtu
 

• bytes--MTU size in bytes, in the range 68 through 1,500 (see RFC 984)

Must be in interface configuration mode (config-if), which requires privileged-level access.

Use once per interface.

1,500

Use the no form of the command to reset the MTU setting to its default.