Configure vCenter alarms for "NIC down as the link is unstable" VMkernel Observations(VOB) message

Products

• VMware vCenter Server 8.0

Issue/Introduction

When ESXi host detected a physical NIC was flapping, the NIC will be take offline  to isolate the network issue.

A event was reported on the vobd.log file.

Example:

--/var/run/log/vobd.log
YYYY-MM-DDTHH:MM:SS In(14) vobd[2098027]:[netCorrelator] 764820363271us: [esx.problem.net.vmnic.linkstate.flapping] Taking down physical NIC vmnic5 because the link is flapping.

Environment

VMware vCenter 8.0

Cause

If it's plan to trigger the vCenter alarm for this event, it could be added by manually.

Resolution

Follow the steps mentioned below to register the alarm manually:

1. Navigate to vCenter Server -> Configure -> Alarm Definitions

2. Click Add

3. Input alarm name "Physical NIC down as the link is unstable".

4. Choose the "Target type" as Hosts and click Next

5. In the "Alarm Rule1" page, Input "esx.problem.net.vmnic.linkstate.flapping" as the trigger condition.
   
   

6. Select severity as "Show as Critical"

7. Optionally, you can configure email notification or SNMP traps or running any script whenever such alarm is triggered

8. Click Next

9. In the Review page, verify if the alarm rules is set correctly and make sure the "Enable this alarm" option is enabled.

10. Click CREATE.

Additional Information

A physical NIC may be brought down due to frequent link status flapping
https://knowledge.broadcom.com/external/article/324499/