Cisco Catalyst 3560X-24P Command Reference Manual page 939

Chapter 2 Catalyst 3750-X and 3560-X Cisco IOS Commands
Usage Guidelines The switch does not support the MTU on a per-interface basis.
The system mtu bytes global configuration command only affects the system MTU size on Fast Ethernet
ports on Catalyst 3750 members in a mixed hardware switch stack. In this stack, you can use the system
mtu bytes global configuration command on a Catalyst 3750-E or Catalyst 3750-X member to configure
the system MTU size on a Catalyst 3750 member. If you enter the system mtu bytes global configuration
command on a Catalyst 3750-E or a 3560-E switch, the command does not take effect.
The system mtu, system mtu jumbo, and system mtu routing global configuration commands do not
take effect in these cases:
•
•
•
Note
When you use the system mtu bytes or system mtu jumbo bytes command to change the system MTU
or system jumbo MTU size, you must reset the switch before the new configuration takes effect. The
system mtu routing command does not require a switch reset to take effect.
The system MTU setting is saved in the switch environmental variable in NVRAM and becomes
effective when the switch reloads. Unlike the system MTU routing configuration, the MTU settings that
you enter with the system mtu and system mtu jumbo commands are not saved in the switch Cisco IOS
configuration file, even if you enter the copy running-config startup-config privileged EXEC
command. Therefore, if you use TFTP to configure a new switch by using a backup configuration file
and want the system MTU to be other than the default, you must explicitly configure the system mtu
and system mtu jumbo settings on the new switch and then reload the switch.
The MTU values applied to the stack members depend on the stack configuration:
•
•
•
Table 2-56
Table 2-56 System MTU Values
Configuration
Standalone Catalyst
3750-X, 3750-E,
3560-X or 3560-E
switch or
Catalyst 3750-X-only
or Catalyst 3750-E-only
stack
OL-21522-02
When you enter the system mtu command on a Catalyst 3750-E or 3560-E switch
In a mixed stack when you enter the system mtu jumbo command for the Fast Ethernet ports on a
Catalyst 3750 member
When you enter the system mtu routing command on a switch on which only Layer 2 ports are
configured
This command is not supported on switches running the LAN base feature set.
A switch stack consisting only of Catalyst 3750-E or Catalyst 3750-X switches
A switch stack consisting of Catalyst 3750-E or Catalyst 3750-X switches and Catalyst 3750
switches, which can be referred to as a mixed hardware switch stack
A switch stack consisting only of Catalyst 3750 switches, also referred to as a Catalyst 3750-only
switch stack
shows how the MTU values are applied depending on the configuration.
system mtu command
You can enter the command on
on a Catalyst 3750-X,
Catalyst 3750-E, Catalyst
3560-X, or Catalyst 3560-E
switch, but system MTU value
1
does not take effect.
system jumbo mtu command
Use the system mtu jumbo
bytes command.
The range is from 1500 to 9198
bytes.
Catalyst 3750-X and 3560-X Switch Command Reference
system mtu
system routing mtu command
Use the system mtu routing
bytes command.
The range is from 1500 to the
system jumbo MTU value (in
2
bytes).
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