I'm looking for a way to query the username associated with a given IP
address. Using NTOP, I am able to watch bandwidth and download usage.
NTOP gives me the IP address for the computers involved and I need to be
able to query NDS to find out the username based on it's IP. Using
Softerra LDAP Browser, I can query DNS information via LDAP. It would
appear that IP information is stored as the value "networkAddress" in the
form ## ## ## ## ## ##, i.e. 31 23 C0 A8 01 C5. I can convert that to an
IP address but can't convert an IP directly into 48bit format that I can
use to query LDAP. How can I do that?

Are there any tools that can directly query the username associated with
an IP address?