Network Management

Had SNMP v2c up and running on 400+ switches.  Switch models include HP 3800, HP 5900, HP 7503, and HP 2530.  IMC was able to communicate with all switches.  Just yesterday IMC start to alert that 1 of the HP 2530 switches denied SNMP access.  I performed a batch "check access settings" and found that all switches respond fine, except the HP 2530's.  No config changes were made to the switches or iMC before this started happening.  When I go into device view for one of the specific 2530 switches, SNMP appears to still be functioning because "Device Status" is still normal, "Device Model" and "Device Category" are still being recognized correctly, and Performance Monitoring Indexes are still being updated.  I also performed an snmpwalk and it was successful.  Any ideas why SNMP is working but iMC thinks its not?

Forgot to add that I restarted IMC and the VM that its hosted on.  No change.

I've seen something similar to that where a device was having trouble responding within the timeout period. Some data would be returned, but not all. 

This could be due to high CPU on the switch, or high latency to the device. Take a closer look at the device, and see if it's behaving oddly. Also try raising the timeouts for that switch, and see what happens.