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Erroneous 'Link Down' alarm when using redundancy-interface


Article ID: 167950


Updated On:




There is an erroneous Link Down alarm generated for the primary interface of redundancy-interface config when a faiilover occurs from primary to backup interface. Workarounds are available and the fix is implemented in future XOS versions.There is an active 'Link Down' alarm for an interface, which is the primary interface of the redundancy interface configuration, but the interface seems to be up as per the show interface status and the alarm doesn't clear.


ID      Date             Source   Description
--      ----             ------   -----------
1382    Feb 21 10:35:34  ap10     Routing protocol NSM failed
1380    Feb 21 10:35:32  ap5      Routing protocol NSM failed
1377    Feb 21 10:35:12  np3      Link down 3/1                              
1322    Feb 21 10:29:54  np3      Link down 3/7 <- FALSE


x80_245#  sho interface ethernet 3/7
Ethernet 3/7 is up    <--------------------UP
  Interface is in use
  Hardware is 10Gigabitethernet, hardware address is N/A
  SNMP Interface Index 17
  SFP info:


CBS# show redundancy-interface
Master Intf   Backup Intf   Active Intf   MacUsage   FailOverMode
-----------   -----------   -----------   --------   ------------
ether 3/7     ether 4/7     Backup       master     preemption-off


In a redundancy-interface configuration setup, when the traffic is failed over from the primary interface to the backup interface, the primary interface is erroneously generating a Link Down alarm.


The fix for this issue has been implemented in XOS version 9.6.3 and above, and it is also targeted for XOS 9.5.7 (at the time of this writing a release date is not available for 9.5.7 - it is recommended to stay updated with the latest maintenance releases).


There are 2 workarounds:

1. Bounce the interface
i.e. Disable/enable the primary interface that has the Link Down active alarm.

2. Re-configure the redundant interface
i.e. Remove the redundancy-interface configuration for the interface that has the alarm, save configuration, and then re-enter the redundancy-interface configuration that was removed.