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Cisco Bug: CSCvs68476 - Loop occurs when shut down Port-channel

Last Modified

Jan 17, 2020

Products (1)

  • Cisco Catalyst 3650 Series Switches

Known Affected Releases

16.6.7

Description (partial)

Symptom:
A loop will occur if you follow the steps below on Cat3650.
------------
  1.show logs for both SwitchA and B
  2.After confirm that HSRP and LAG state, execute a <clear counter> on SwitchA
  3.Shut down / no shut port-channel 1 on SwitchA
  4.Check <show interface portchnnel 1> and confirm that the counter is soaring
  5.Collect logs
------------

SwitchA 1/0/1-------------1/0/1 SwitchB
            1/0/2-------------1/0/2

SwitchA#show interfaces port-channel X
Port-channel1 is up, line protocol is up (connected) 

     25135590 packets input, 1810948106 bytes, 0 no buffer
     Received 25135580 broadcasts (25135568 multicasts)

Conditions:
We need to disable STP to reproduce this phenomenon.
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