Intermapper uses two different DNS resolvers. When you add a device using the Add Device... command, Intermapper uses the system's resolver. When Intermapper is monitoring DNS names and addresses as part of the "DNS Check" feature, Intermapper does its own DNS operations, via UDP packets, to the domain name servers listed in Intermapper's own DNS/WINS Settings Preferences panel. Intermapper's built-in domain name resolver currently assumes that the domain name is fully-qualified. For each domain name, the interval for double-checking the domain name is determined by the TTL in each DNS response. The minimum interval is controlled by the minimum interval between DNS checks dropdown in the DNS/WINS Settings Preferences panel.
When you discover devices, Intermapper initially looks up the Fully-Qualified-Domain Name (FQDN) from the IP address (address > name), then it settles down to monitoring the domain name (name > address). Intermapper's built-in DNS resolver doesn't handle partially qualified domain names or things that aren't really domain names; hence, they will fail to resolve.
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