8-22
Catalyst 2360 Switch Software Configuration Guide
OL-19808-01
Chapter 8 Configuring Interface Characteristics
Configuring the System MTU
Beginning in privileged EXEC mode, follow these steps to exclude a port from SVI state-change
calculations:
This example shows how to configure an access or trunk port in an SVI to be excluded from the line-state
status calculation:
Switch#
configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#
interface gigabitethernet0/2
Switch(config-if)#
switchport autostate exclude
Switch(config-if)#
exit
Configuring the System MTU
The default maximum transmission unit (MTU) size for frames received and sent on all interfaces on the
switch. You can change the MTU size to support switched jumbo frames on all Gigabit Ethernet and
10-Gigabit Ethernet interfaces.
•
The system jumbo MTU value applies to switched packets on the Gigabit Ethernet and 10-Gigabit
Ethernet ports of the switch. Use the
system mtu jumbo
bytes
global configuration command to
specify the system jumbo MTU value.
•
You can enter the
system mtu routing
bytes
global configuration command and the
system
mtu
bytes
global configuration on the switch, but these commands are not supported and have no affect.
When configuring the system MTU values, follow these guidelines:
•
The switch does not support the MTU on a per-interface basis.
•
When you use the
system
mtu jumbo
bytes
command to change the system jumbo MTU size, you
must reload the switch before the new configuration takes effect. The system MTU setting is saved
in the switch environmental variable in NVRAM and becomes effective when the switch reloads.
•
The MTU settings you enter with the
system mtu jumbo
command 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 jumbo
settings on the new switch and then reload the switch.
•
The upper limit of the system routing MTU value is based on the switch configuration and refers to
either the currently applied system jumbo MTU value. For information about setting the MTU sizes,
see the
system mtu
global configuration command in the command reference for this release.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface
interface-id
Specify a Layer 2 interface (physical port or port
channel), and enter interface configuration mode.
Step 3
switchport autostate exclude
Exclude the access or trunk port when defining the
status of an SVI line state (up or down)
Step 4
end
Return to privileged EXEC mode.
Step 5
show running config interface
interface-id
show interface
interface-id
switchport
(Optional) Show the running configuration.
Verify the configuration.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.