If everything is set up correctly (device responds to SNMP requests from NetXMS server and provides information via CDP MIB) you should see picture like attached.
Also, may be I didn't understand your question correctly - NetXMS is able to collect information from CDP-enabled devices (like switches or routers) and display it. NetXMS server or agents by itself does not work as CDP peers.
Best regards,
Victor
[image: topology.png]
