mtu

Configures the global or interface MTU value.

Syntax

mtu value
no mtu value

Parameters

mtu value
Specifies MTU value of an interface. Valid range is 1024-9216. Default MTU value is 9216.

Modes

Interface config mode

Usage Guidelines

The MTU configured in the specified interface overrides the global MTU.

The no mtu value command sets the MTU to the default value, 9216.

This command is available only to users with admin role.

Running this command causes changes that trigger port flap. As a best practice, run this command during a maintenance window to avoid service disruptions.

Table 1. Error messages
Error message Reason
% Unknown command. Throws an error if MTU value is outside valid range, as shown in the following example:
device(config-if-eth-1/1)# mtu 100 

Examples

The following examples show how to configure global and interface MTU value.

device# configure terminal 
device(config)# mtu 4000

device# configure terminal 
device(config)# interface ethernet 1/10 
device(config-if-eth 1/10)# mtu 4000
device(config-if-eth-1/1)# mtu 100 
% Unknown command.

device# show running interface ethernet 1/10 
interface ethernet 1/10 
mtu 4000 
shutdown