Network Failure Detection Policy - Link status only triggers conditions and Network uplink redundancy lost/degraded log records

Products

• VMware vCenter Server 7.0
• VMware vCenter Server 8.0

Issue/Introduction

This article shows Network Failure Detection Policy - Link status only mode triggers conditions in detail and vSS/vDS Network uplink redundancy lost/degraded log records to prove it.

Environment

VMware ESXi 8.0.x

VMware ESXi 7.0.x

Resolution

Network Failure Detection Policy - Link status only

Relies only on the link status that the network adapter provides. Detects failures, such as:

• removed cables
• physical switch power failures.
• physical switch port which is related ESXi uplink vmnic is shut down.

Link status does not detect the following configuration errors:

• Physical switch port that is blocked by spanning tree or is misconfigured to the wrong VLAN .
• Pulled cable that connects a physical switch to another networking device, for example, an upstream switch.
• If physical switch port is broken but the link status still shows up status, it also may not trigger network failure detection.

 

Alarms Network uplink redundancy lost/degraded Validation

Generally, if the Network Failure Detection Policy - Link status only  is triggered, It also coexists with Alarms Network uplink redundancy lost/degraded

To validate Alarm Network uplink redundancy lost/degraded is triggered. We need to check as follows:

1. There are at least two vmnic(uplinks) bounding at vSS or vDS, and two uplinks both in Active status
   • Uplinks in Active/Standby mode, if the Standby vmnic is broken and will not trigger alarms.
2. There is at least one VM or vmk at vSS/vDS
3. In the ESXi host's /var/log/vobd.log file, we see entries similar to:
   

   YYYY-MM-DDTHH:MM:SS.028Z: [netCorrelator] 47201977007087us: [vob.net.pg.uplink.transition.down] Uplink: vmnic2 is down. Affected portgroup: port_group. 1 uplinks up. Failed criteria: 128
   
   YYYY-MM-DDTHH:MM:SS.028Z: [netCorrelator] 47201977007132us: [vob.net.vmnic.linkstate.down] vmnic vmnic2 linkstate down

4. In the ESXi host's /var/log/vobd.log file, we see entries similar to:

   YYYY-MM-DDTHH:MM:SS.028Z: [netCorrelator] 47201977007087us: [vob.net.pg.uplink.transition.down] Uplink: vmnic2 is down. Affected portgroup: port_group. 1 uplinks up.
   
   YYYY-MM-DDTHH:MM:SS.028Z: [netCorrelator] 47201977007132us: [vob.net.vmnic.linkstate.down] vmnic vmnic2 linkstate down

5. If there is no VM or vmk at vSS/VDS, the "Network uplink redundancy lost/degraded"  will not trigger alarm.
   In the ESXi host's /var/log/vobd.log file, we only see entries similar to:

   YYYY-MM-DDTHH:MM:SS.028Z: [netCorrelator] 47201977007132us: [vob.net.vmnic.linkstate.down] vmnic vmnic2 linkstate down

 

 

Additional Information

For more information on Link status refer KB: Link state up or down for a vmnic interface on ESXi

For more information on Link status marked down because of a failed criteria code refer KB: Network adapter (vmnic) is down or fails with a Failed Criteria Code