Name

ip mtu — interface

Synopsis

ip mtu bytes
no ip mtu bytes

Configures

Maximum Transmission Unit (MTU) for the interface

Default

Depends on the interface’s media type

Description

This command sets the MTU for the interface to bytes. The MTU is the largest packet size that can be sent over the interface. The default MTU depends on the media type; Table 17-11 shows default MTU values for some common media. This command allows you to modify the MTU for any interface. Larger MTU values are more efficient with highly reliable networks; lower MTU values can help if an interface is unreliable, or in situations where protocols do not support fragmentation.

Table 17-11. Default MTU values

Interface type

Default MTU

Ethernet/Serial

1500

HSSI/ATM/FDDI

4470

Example

interface ethernet 0
  ip mtu 1250

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