The Clear Counters Cisco command

Command: clear counters

Function: The 'clear counters' command is primarily used to erase the previously collected monitoring data from various interfaces and sub-interfaces on Cisco networking devices like routers and switches. Additionally, it assists in troubleshooting network performance issues and monitoring data utilization.

Usage:

• To clear counters on a specific interface, use the following syntax:

clear counters interface <interface-name>

• To remove counters from all interfaces within a range, use this syntax:

clear counters interface range <interface-range>

• To remove counters from all interfaces of a particular type, use this syntax:

clear counters interface type <interface-type>

• To remove counters from all interfaces, use this syntax:

clear counters interface all

Command Applicability:

• Routers running Cisco IOS (Internetwork Operating System)
• Switches running Cisco IOS or Cisco IOS XE (Extended)
• Other Cisco networking devices supporting this command

Impact of 'clear counters':

• Once executed, it removes all collected statistics and per-interface traffic data. This includes historical data like input/output packets, errors, and discards.
• Clearing counters can be beneficial in the following scenarios:
  • Starting a fresh monitoring baseline to capture new traffic patterns.
  • After resolving a network performance issue to monitor the impact of mitigation efforts.
  • During network maintenance or configuration changes to observe the effects on data flow.

Additional Information:

• 'clear counters' primarily targets interface-related statistics. To clear other types of counters, such as memory or CPU utilization, specific commands are needed.
• Resetting counters may interrupt certain monitoring systems that rely on historical data, such as network management systems (NMS) or graphing tools.
• Using 'clear counters' on a device with a high volume of traffic may cause temporary resource utilization spikes due to processing overhead.
• Always consider the potential impact on network monitoring and data analysis before using this command.

Note: Please refer to the official Cisco documentation for the specific syntax and detailed usage of the 'clear counters' command in your specific networking environment.

clear counters Usage Examples

1. Clear Interface Counters:

• clear counters interface GigabitEthernet0/1 - Clears the counters for the specified interface.
• clear counters interface type ethernet - Clears the counters for all Ethernet interfaces.
• clear counters interface range FastEthernet0/1-3 - Clears the counters for a range of interfaces.

2. Clear IP Counters:

• clear counters ip - Clears all IP counters.
• clear counters ip interface GigabitEthernet0/1 - Clears IP counters for the specified interface.
• clear counters ip neighbor 10.10.10.1 - Clears IP neighbor counters for the specified IP address.

3. Clear ICMP Counters:

• clear counters icmp - Clears all ICMP counters.
• clear counters icmp errors - Clears ICMP error counters.
• clear counters icmp unreachable - Clears ICMP unreachable counters.

4. Clear TCP Counters:

• clear counters tcp - Clears all TCP counters.
• clear counters tcp connections established - Clears TCP connections established counters.
• clear counters tcp segments retransmitted - Clears TCP segments retransmitted counters.

5. Clear UDP Counters:

• clear counters udp - Clears all UDP counters.
• clear counters udp datagrams received - Clears UDP datagrams received counters.
• clear counters udp datagrams transmitted - Clears UDP datagrams transmitted counters.

6. Clear Serial Counters:

• clear counters serial 0/0 - Clears the counters for the specified serial interface.
• clear counters serial all - Clears the counters for all serial interfaces.

7. Clear ATM Counters:

• clear counters atm - Clears all ATM counters.
• clear counters atm virtual-circuit 0/1 - Clears the counters for the specified ATM virtual circuit.
• clear counters atm address 10.10.10.1 - Clears the counters for the specified ATM address.

8. Clear Frame Relay Counters:

• clear counters frame-relay - Clears all Frame Relay counters.
• clear counters frame-relay interface Serial0/0 - Clears the counters for the specified Frame Relay interface.
• clear counters frame-relay pvc 10 - Clears the counters for the specified Frame Relay PVC.

9. Clear ISDN Counters:

• clear counters isdn - Clears all ISDN counters.
• clear counters isdn interface Serial0/0 - Clears the counters for the specified ISDN interface.
• clear counters isdn b-channel 10 - Clears the counters for the specified ISDN B-channel.

10. Clear Routing Counters:

- `clear counters routing` - Clears all routing counters.
- `clear counters routing ospf` - Clears OSPF routing counters.
- `clear counters routing rip` - Clears RIP routing counters.