When connecting from an on-campus static IP connection, you can't get the file lists from users connected from the VPN. However, you can download files from them that were already queued before they moved off campus.
Certain hosts (some wifi clients, static IPs not sent to hostmaster) do not have rDNS entries, and therefore do not have locations parsed by Dtella/DC++. Consider changing hostnameToLocation() to a function that finds the location based on the CNS subnet the host is using if there is no hostname.