System Mtu - Cisco Catalyst 2960 Command Reference Manual

Chapter 2 Catalyst 2960 Switch Cisco IOS Commands

system mtu

Use the system mtu global configuration command to set the maximum packet size or maximum
transmission unit (MTU) size for Gigabit Ethernet ports or for Fast Ethernet (10/100) ports. Use the no
form of this command to restore the global MTU value to its default value.
Syntax Description
bytes
jumbo bytes
Defaults
The default MTU size for all ports is 1500 bytes.
Command Modes Global configuration
Command History Release
12.2(25)FX
Usage Guidelines When you use this command to change the MTU size, you must reset the switch before the new
configuration takes effect.
Gigabit Ethernet ports are not affected by the system mtu command, and 10/100 Mbps ports are not
affected by the system mtu jumbo command. If you do not configure the system mtu jumbo command,
the setting of the system mtu command applies to all Gigabit Ethernet interfaces.
If you enter a value that is outside the range for the specific type of switch, the value is not accepted.
Note The switch does not support setting the MTU on a per-interface basis.
The size of frames that can be received by the switch CPU is limited to 1998 bytes, no matter what value
was entered with the system mtu command. Although frames that are forwarded or routed typically are
not received by the CPU, in some cases packets are sent to the CPU, such as traffic sent to control traffic,
SNMP, Telnet, or routing protocols.
78-16882-01
system mtu {bytes | jumbo bytes}
no system mtu
Set the system MTU for ports that are set to 10 or 100 Mbps. The range
is 1500 to 1998 bytes.
Set the system jumbo frame size (MTU) for Gigabit Ethernet ports. The
range is 1500 to 9000 bytes.
Modification
This command was introduced.
Catalyst 2960 Switch Command Reference
system mtu
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