Smarts IP: "Down" alarm is not generated for an interface that is down, but Interface "DownOrFlapping" alarm is generated instead

Products

• VMware Smart Assurance

Issue/Introduction

Provide information on Smarts Alerting functionality.

Symptoms:




Smarts IP does not generate Down alarm for an interface that is down
Smarts IP generates Interface "DownOrFlapping" alarm instead of "Down" alarm when an interface is down

Environment

VMware Smart Assurance - SMARTS

Cause

This behavior is seen when a given interface that was down has a Peer Device which went down and that in turn caused the given device to go down. In this situation, there will not be a Down alarm generated for the first interface. If a given interface has a Peer Device which is down, the given interface's "Down" event will be suppressed by the Peer Device "Down" event.

Example
This can be represented with the following example:

Device A                           Device B 
    |             NWC                |
Interface A       ---->         Interface B  

(Assume there is a N/w connection between Interface A and Interface B)

If Device B goes down, the interface on Device A and the network connection between A and B also goes down. Therefore, the Device B "Down" event is the "real" down event that causes Device A interface down and the network connection down, so the "Down" event for Device A is suppressed. However, if Device B is responsive, then a "Down" event is generated for the interface on Device A.

Resolution

No fix is available or required. Smarts is functioning as designed.