I have set correct SNMP community string but using Discovery Console, Spectrum keeps model F5 BIG-IP device as pingable model, not SNMP capable model as expected. Clicking the [Contact] button on MIB Tools to contact the device shows green that indicates the device is contactable using the SNMP community string. However if I use MIB Tools to get sysObjectID (220.127.116.11.18.104.22.168) value from the device, it doesn't return any value (empty).
We specify OID for the top-most node of the SNMP tree in F5 BIG-IP device SNMP access configuration. This OID value should be at least 22.214.171.124 so that Spectrum can access both standard MIB-II and enterprise MIB data. The issue happens when this OID value is specified too restrictive so that Spectrum cannot access sysObjectID and other MIB-II OIDs that are required for SNMP modeling.
Configure the F5 BIG-IP device so that 126.96.36.199 is specified as OID for the top-most node of the SNMP tree and redo the discovery/modeling.