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





Goto Port 137
Probe Port 138
Enter Port: 0-65535
Goto Port 139



Port Authority Database

Port 138

Name: 
netbios-dgm

Purpose: 
NETBIOS Datagram Service

Description: 
UDP NetBIOS datagrams packets are exchanged over this port, usually with Windows machines but also with any other system running Samba (SMB). These UDP NetBIOS datagrams support non-connection oriented file sharing activities.

Related Ports: 
137, 139, 445




Background and Additional Information:

This is the second port of the original "NetBIOS trio" used by the first Windows operating systems (up through Windows NT) in support of file sharing.

For additional information about this trio of Internet ports, please see the "Background and Additional Information" for the first port of the trio, port 137.

Trojan Sightings: Chode

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