9-21
Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 9 Configuring Interfaces
Configuring the Interface MTU
Configuring the Interface MTU
You can configure the maximum transmission unit (MTU) size on an interface to determine the packet
size that can be received on the interface. Because the switch does not fragment Layer 2 packets, it drops
switched Layer 2 packets larger than the packet size supported on the egress interface.
Beginning in privileged EXEC mode, follow these steps to change the MTU size on an interface:
This example shows how to set the maximum packet size for a Gigabit Ethernet port to 1800 bytes:
Switch(config)#
interface gigabitethernet0/3
Switch(config-if)#
mtu 1800
Switch(config)#
exit
Monitoring and Maintaining the Interfaces
These sections contain interface monitoring and maintenance information:
•
Monitoring Interface Status, page 9-21
•
Clearing and Resetting Interfaces and Counters, page 9-23
•
Shutting Down and Restarting the Interface, page 9-23
Monitoring Interface Status
Commands entered at the privileged EXEC prompt display information about the interface, including
the versions of the software and the hardware, the configuration, and statistics about the interfaces.
Table 9-4
lists some of these interface monitoring commands. (You can display the full list of show
commands by using the show ? command at the privileged EXEC prompt.) These commands are fully
described in the Cisco IOS Interface Command Reference, Release 12.2.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface interface-id
Specify the interface to be configured, and enter
interface configuration mode. The interface must be a
physical interface, but it can be one on which a service
instance is configured.
Step 3
mtu bytes
Configure the MTU size for the interface. The range is
from 1500 to 9800 bytes. The default is 1500.
Step 4
end
Return to privileged EXEC mode.
Step 5
show interface interface-id
Verify the configuration.
Step 6
copy running-config startup-config
Save your entries in the configuration file.