ip mtu

Use ip mtu to set the MTU of IPv4 packets sent over an interface.

Use undo ip mtu to restore the default.

Syntax

ip mtu mtu-size

undo ip mtu

Default

The MTU of IPv4 packets sent over an interface is not set.

Views

Interface view

Predefined user roles

network-admin

mdc-admin

Parameters

mtu-size: Specifies the MTU in bytes. The value range for the mtu-size argument is 128 to 1560.

Usage guidelines

When a packet exceeds the MTU of IPv4 packets sent over an interface, the device processes the packet in one of the following ways:

• If the packet disallows fragmentation, the device discards it.

• If the packet allows fragmentation, the device fragments it and forwards the fragments.

Fragmentation and reassembling consume system resources, so set an appropriate MTU to avoid fragmentation.

If an interface supports both the mtu and ip mtu commands, the device fragments a packet based on the MTU set by the ip mtu command.

Examples

# Set the MTU of VLAN-interface 100 to 1280 bytes.

<Sysname> system-view
[Sysname] interface vlan-interface 100
[Sysname-Vlan-interface100] ip mtu 1280