Port Authority Edition – Internet Vulnerability Profiling
by Steve Gibson,  Gibson Research Corporation.

Goto Port 388
Probe Port 389
Enter Port: 0-65535
Goto Port 390

Port Authority Database

Port 389


Lightweight Directory Access Protocol

LDAP (which is what people call it) is a modern and popular Internet directory access protocol used by many systems and services. Most Windows users will encounter it because Microsoft's NetMeeting uses and opens the LDAP port 389 while it is running.

Related Ports: 
1002, 1720

Background and Additional Information:

Since LDAP's use of port 389, and H.323 teleconferencing's call setup use of port 1720, are intimately associated through their common Microsoft NetMeeting usage, please see our discussion of port 1720 security. The issues raised and discussed there also apply to LDAP port 389.

For further reading or research about LDAP:



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