Cisco Systems 2950 Switch User Manual


 
10-15
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
OL-10101-02
Chapter 10 Configuring Interface Characteristics
Monitoring and Maintaining the Interfaces
Use the no description interface configuration command to delete the description.
This example shows how to add a description on a port and to verify the description:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface fastethernet0/4
Switch(config-if)# description Connects to Marketing
Switch(config-if)# end
Switch# show interfaces fastethernet0/4 description
Interface Status Protocol Description
Fa0/4 up down Connects to Marketing
Configuring Loopback Detection
You can use this feature to detect a loopback on a 10/100 interface at the physical layer. If you configure
the down-when-looped interface command, the system checks if the link-up is due to a loopback
condition at the physical layer. If the link-up is due to a loopback condition, the system does not let the
Ethernet link come up. The system can detect the loopback only on links that are directly connected to
that interface and not on links that are indirectly connected. The loopback detection works when the
interfaces are configured to autonegotiate.
For complete syntax and usage information for the down-when-looped interface command, see the
Cisco IOS Interface Command Reference, Release 12.1.
Note The down-when-looped interface command is not supported on the Catalyst 2950G switches.
Monitoring and Maintaining the Interfaces
You can perform the tasks in these sections to monitor and maintain interfaces:
Monitoring Interface and Controller Status, page 10-16
Clearing and Resetting Interfaces and Counters, page 10-16
Shutting Down and Restarting the Interface, page 10-17
Step 4
end Return to privileged EXEC mode.
Step 5
show interfaces interface-id description
or
show running-config
Verify your entry.
Step 6
copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose