17.3.2 Checking L2 Looping Status

You can use the show loop-detection command to check the L2 loop detection settings and the operating status.

You can check for ports that are unable to send frames because the rate for sending L2 loop detection frames on the port has exceeded the maximum value. If the configuration of VLAN port counts does not exceed the capacity, there is no problem.

You can also check for ports that have been deactivated due to a loop failure in the status section of the port information section.

Figure 17-7: L2 Loop-Detected Information
> show loop-detection Date 20XX/04/21 12:10:10 UTC Interval Time :10 Output Rate :30pps Threshold :1 Hold Time :infinity Auto Restore Time :- VLAN Port Counts Configuration :103 Capacity :300 Port Information Port Status Type DetectCnt RestoringTimer SourcePort Vlan 1/0/1 Up send-inact 0 - - 1/0/2 Down send-inact 0 - - 1/0/3 Up send 0 - - 1/0/4 Up exception 0 - - 1/0/5 Down(loop) send-inact 1 - CH:32(U) 100 CH:1 Up trap 0 - - CH:32 Up uplink - - 1/0/5 100 >

Figure 17-7: L2 Loop-Detected Information

> show loop-detection
Date 20XX/04/21 12:10:10 UTC
Interval Time           :10
Output Rate             :30pps
Threshold               :1
Hold Time               :infinity
Auto Restore Time       :-
VLAN Port Counts
    Configuration       :103         Capacity       :300
Port Information
  Port    Status     Type        DetectCnt RestoringTimer  SourcePort  Vlan
  1/0/1   Up         send-inact          0              -  -
  1/0/2   Down       send-inact          0              -  -
  1/0/3   Up         send                0              -  -
  1/0/4   Up         exception           0              -  -
  1/0/5   Down(loop) send-inact          1              -  CH:32(U)     100
  CH:1    Up         trap                0              -  -
  CH:32   Up         uplink              -              -  1/0/5        100
>