Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS
 
Chapter 9      Configuring Interfaces
Monitoring and Maintaining the Interface
This example shows how to clear and reset the counters on Fast Ethernet interface 5/5:
Switch# clear counters fastethernet 5/5 
Clear "show interface" counters on this interface [confirm] y 
Switch#
*Sep 30 08:42:55: %CLEAR-5-COUNTERS: Clear counter on interface FastEthernet5/5
by vty1 (171.69.115.10)
Switch#
The clear counters command (without any arguments) clears all the current interface counters from all interfaces.
Note The clear counters command does not clear counters retrieved with SNMP; it clears only those counters 
displayed with the EXEC show interfaces command.
Shutting Down and Restarting an Interface
You can disable an interface, which disables all functions on the specified interface and marks the interface as unavailable on 
all monitoring command displays. This information is communicated to other network servers through all dynamic routing 
protocols. The interface is not mentioned in any routing updates. 
To shut down an interface and then restart it, perform this task: 
This example shows how to shut down Fast Ethernet interface 5/5:
Switch(config)# interface fastethernet 5/5 
Switch(config-if)# shutdown 
Switch(config-if)#
*Sep 30 08:33:47: %LINK-5-CHANGED: Interface FastEthernet5/5, changed state to a administratively down
Switch(config-if)# 
This example shows how to reenable Fast Ethernet interface 5/5:
Switch(config-if)# no shutdown 
Switch(config-if)#
*Sep 30 08:36:00: %LINK-3-UPDOWN: Interface FastEthernet5/5, changed state to up
Switch(config-if)# 
To verify whether an interface is disabled, enter the EXEC show interfaces command. An interface that has been shut down 
appears as “administratively down.”
Command Purpose
Switch# clear counters {type slot/interface}
Clears interface counters.
Command Purpose
Step 1
Switch(config)# interface {vlan vlan_ID} | 
{{fastethernet | gigabitethernet | 
tengigabitethernet} slot/port} | {port-channel 
port_channel_number}
Specifies the interface to be configured.
Step 2
Switch(config-if)# shutdown 
Shuts down the interface.
Step 3
Switch(config-if)# no shutdown 
Reenables the interface.