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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter12 Configuring Interface Characteristics
Configuring Layer 3 Interfaces

Adding a Description for an Interface

You can add a description about an interface to help you remember its function. The description appears
in the output of these privileged EXEC commands: show configuration, show running-config, and
show interfaces.
Beginning in privileged EXEC mode, follow these steps to add a description for an interface:
Use the no description interface configuration command to delete the description.
This example shows how to add a description on a port and how to verify the description:
Switch# config terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface gigabitethernet1/0/2
Switch(config-if)# description Connects to Marketing
Switch(config-if)# end
Switch# show interfaces gigabitethernet1/0/2 description
Interface Status .Protocol Description
Gi1/0/2 admin down down Connects to Marketing
Configuring Layer 3 Interfaces
The switch supports these types of Layer 3 interfaces:
SVIs: You should configure SVIs for any VLANs for which you want to route traffic. SVIs are
created when you enter a VLAN ID following the interface vlan global configuration command. To
delete an SVI, use the no interface vlan global configuration command. You cannot delete interface
VLAN 1.
Note When you create an SVI, it does not become active until it is associated with a physical port.
For information about assigning Layer 2 ports to VLANs, see Chapter13, “Configuring
VLANs.”
When configuring SVIs, you can also configure SVI autostate exclude on a port in the SVI to
exclude that port from being included in determining SVI line-state status. See the “Configuring SVI
Autostate Exclude” section on page12-27.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Specify the interface for which you are adding a description, and enter
interface configuration mode.
Step3 description string Add a description (up to 240 characters) for an interface.
Step4 end Return to privileged EXEC mode.
Step5 show interfaces interface-id description
or
show running-config
Verify your entry.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.