Mtu - Cisco Catalyst 4500 Series Command Reference Manual

Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches

mtu

To enable jumbo frames on an interface by adjusting the maximum size of a packet or maximum
transmission unit (MTU), use the mtu command. To return to the default setting, use the no form of this
command.
Syntax Description
bytes
Defaults
The default settings are as follows:
•
•
Command Modes Interface configuration mode
Command History Release
12.1(13)EW
Usage Guidelines Jumbo frames are supported on nonblocking Gigabit Ethernet ports, switch virtual interfaces (SVI), and
EtherChannels. Jumbo frames are not available for stub-based ports.
The baby giants feature uses the global system mtu size command to set the global baby giant MTU. It
allows all stub-based port interfaces to support an Ethernet payload size of up to 1552 bytes.
Both the system mtu command and the per-interface mtu command work on interfaces that can support
jumbo frames, but the per-interface mtu command takes precedence.
Examples This example shows how to specify an MTU of 1800 bytes:
Switch(config)# interface GigabitEthernet 1/1
Switch(config-if)# mtu 1800
Related Commands Command
system mtu
OL-27596 -01
mtu bytes
no mtu
Byte size; valid values are from 1500 to 9198.
Jumbo frames are disabled
1500 bytes for all ports
Modification
Support for this command was introduced on the Catalyst 4500 series switches.
Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.4.0SG and IOS 15.1(2)SG)
Description
Sets the maximum Layer 2 or Layer 3 payload size.
mtu
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