As you start polling and monitoring different devices types you may run into situation where you need to see the response to the OIDs that the device was either discovered with or what it is being returned by the SNMP agent.
Up to CAPM 2.8 the url that is used to pull up this type of information can be found on the Data Aggregator:
In version 3.0 the url has changed slightly to be:
http://<da-host>:8581/dcdebug/searchdebug.html or more simply http://<da-host>:8581/dcdebug
Once you have the url open you'll need a bit of information based on the device that you're troubleshooting and depending on the version of CAPM you can debug down to the component level. The minimum requirements are the device IP address and the IP Domain that is polling the device.