System Mtu - Cisco Catalyst 4500 Series Configuration Manual

Chapter 2

system mtu

To set the maximum Layer 2 or Layer 3 payload size, use the system mtu command. To revert to the
default MTU setting, use the no form of this command.
Syntax Description
datagram-size
Command Default The default MTU setting is 1500 bytes.
Command Modes Global configuration mode
Command History Release
12.1(12c)EW
Usage Guidelines The datagram-size parameter specifies the Ethernet payload size, not the total Ethernet frame size, and
the Layer 3 MTU is changed as a result of changing the system mtu command.
For ports from 3 to18 on model WS-X4418-GB and ports from 1 to 12 on model WS-X4412-2GB-TX,
only the standard IEEE Ethernet payload size of 1500 bytes is supported.
For other modules, an Ethernet payload size of up to 1552 bytes is supported with a total Ethernet frame
size of up to 1600 bytes.
Examples The following example shows how to set the MTU size to 1550 bytes:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# system mtu 1550
Switch(config)# end
Switch#
The following example shows how to revert to the default MTU setting:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# no system mtu
Switch(config)# end
Switch#
system mtu datagram-size
no system mtu
Layer 2 payload size; valid values from 1500 to 1552 bytes.
Modification
This command was introduced on the Catalyst 4500 series switch.
Catalyst 4500 Series Switch Cisco IOS Command Reference—Release XE 3.9.xE and 15.2(5)Ex
system mtu
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