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What does link-monitoring logic failed mean ?

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Applies to

Data ONTAP 7 and earlier

Answer

An error is seen in the messages log:

Sat Feb 20 14:50:31 GMT [pvif.failedLinkMonitoring:error]: e0a: link-monitoring logic failed

Link-monitoring logic was added in ONTAP 7.3.2 and later to detect when links in a VIF are down or misconfigured.

 

Whenever a link goes down because of link-monitoring failure, the above EMS message is displayed. This EMS message was added in 7.3.2, though the link monitoring logic existed in earlier versions of ONTAP.

This feature is used to identify whether the underlying links are properly connected to switch and are available for communication at anytime. It will choose every link of single-mode VIF and send some ARP packets. It will also verify whether those ARP packets are received correctly on other link (other than the one from which it was sent). Based on this, the health of the link is confirmed. This logic will be triggered on a single-mode VIF only if it contains more than one underlying link and at least one link is passive, which is UP. Here UP means the link is currently UP without any issues in connectivity and the switch port is administratively up.

No special configurations (like trunk, aggregate, etc.) are needed on the switch-ports connecting the links of single-mode VIF. The switch-ports should have the normal access VLAN configurations. There is a requirement for the switch ports connecting the links of a VIF to be on the same LAN (or VLAN). The switch ports must also be in the same broadcast domain, and be part of a layer 2 switched network.

Troubleshooting steps to resolve this message:

  • Check whether all the switch ports belong to same VLAN (same broadcast domain)
  • If the VIF links are connected to two switches, check whether those switches are connected via Inter-Switch Link (ISL). Else, check whether the connecting ports of switches (via other switch) belong to the same broadcast domain (BUG 324514).
  • If the cables of underlying links are pulled out / plugged in for certain number of times and a failure happens, try to unplug and plug-in the cables once more to make the link up with the 'enabled' flag set in it (BUG 342508).

If the failure is due to link-down event, then check if:

  • the cable of the underlying link is connected correctly
  • the switch port connecting the link is not 'shutdown'

Note: OnCommand Unified Manager is not capable of alerting on this circumstance.

 

Additional Information

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