I'm not sure if you already add the switch to the NetSight's "snmptrapd.conf". If the switch is not registered on the "snmptrapd.conf" file in NetSight, then NetSight doesn't display the Trap alarm even though it receive trap message sent from the switch.
Followings are the procedure to add device into "snmptrad.conf" file.
1. Right-click on a device which you want to add in Console's device-tree.
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2. Choose "Trap Receiver Configuration" then new window will be pop-up.
3. Select "snmptrapd" tab
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4. Check the credential table (e.g. IP address or Credential Name) if they are correct. Usually the "Credential Name" is chosen incorrectly so you have to correct it.
5. Click the device in the Credential table and click "Get EngineID"
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6. Click "Add to File" and confirm the EngineID is added as well in the end of line under "snmptrapd.conf text"
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7. Save and Close
8. You have to restart "SNMPTrap" service in NetSight server
If your NetSight is Linux based, then please refer follow article:
https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-restart-snmptrapd-in-NetSight-of-li...
If your NetSight is Window based, then you can just use NetSight icon in taskbar to restart SNMPTrap.