For Network Discovery, you can upload a hosts file in the form:
ipaddress [ hostname | DNS-name ]
—Where the names in the hosts file will override the reverse DNS lookup for a matching DNS name.
Example
192.0.2.8 ws2.example.com
203.0.113.8 mail01.example.com
Tip: WhatsUp Gold discovery also supports upload of an unformatted list of IP addresses.