Configuring SNMPv3 for Cisco 3560X

I am using OpManager ver 9101.

Recently installed a Cisco WS-C3560X-24T-L   switch and wanted to test using SNMPv3 to manage the switch.

The following are the commands used on Cisco 3560X:-

snmp-server group OpMgrGrp v3 priv

snmp-server user OpMgrUser OpMgrGrp v3 auth sha ABC priv aes 128 DEF

snmp-server context opmanager

I created the credentials using OpMgrUser with SHA ABC and AES DEF, and context opmanager in OpManager.

Then try to add device, but it is trying until timeout and failed to add the device.

If I use the following command, then OpManger added the device successfully.

snmp-server community public RO 99

Which context name should I put in OpManager credential?

If you have followed the KB WS-C3560X-24T-S , you can leave it blank.