This article was previously published under Q163409
The NetBIOS naming convention allows for 16 characters in a NetBIOS name. Microsoft, however, limits NetBIOS names to 15 characters and uses the 16th character as a NetBIOS suffix.
All NetBIOS names are 16 characters in length. A NetBIOS suffix is the 16th character of the 16-character NetBIOS name. The NetBIOS suffix is used by Microsoft Networking software to identify functionality installed on the registered device.
The following table lists the NetBIOS suffixes that are used by Microsoft Windows NT. The suffixes are listed in hexadecimal format because many of them are unprintable otherwise.
Name Number(h) Type Usage--------------------------------------------------------------------------<computername> 00 U Workstation Service<computername> 01 U Messenger Service<\\--__MSBROWSE__> 01 G Master Browser<computername> 03 U Messenger Service<computername> 06 U RAS Server Service<computername> 1F U NetDDE Service<computername> 20 U File Server Service<computername> 21 U RAS Client Service<computername> 22 U Microsoft Exchange Interchange(MSMail Connector)<computername> 23 U Microsoft Exchange Store<computername> 24 U Microsoft Exchange Directory<computername> 30 U Modem Sharing Server Service<computername> 31 U Modem Sharing Client Service<computername> 43 U SMS Clients Remote Control<computername> 44 U SMS Administrators Remote Control Tool<computername> 45 U SMS Clients Remote Chat<computername> 46 U SMS Clients Remote Transfer<computername> 4C U DEC Pathworks TCPIP service on Windows NT<computername> 42 U mccaffee anti-virus<computername> 52 U DEC Pathworks TCPIP service on Windows NT<computername> 87 U Microsoft Exchange MTA<computername> 6A U Microsoft Exchange IMC<computername> BE U Network Monitor Agent<computername> BF U Network Monitor Application<username> 03 U Messenger Service<domain> 00 G Domain Name<domain> 1B U Domain Master Browser<domain> 1C G Domain Controllers<domain> 1D U Master Browser<domain> 1E G Browser Service Elections<INet~Services> 1C G IIS<IS~computer name> 00 U IIS<computername> [2B] U Lotus Notes Server ServiceIRISMULTICAST [2F] G Lotus NotesIRISNAMESERVER  G Lotus NotesForte_$ND800ZA  U DCA IrmaLan Gateway Server Service
NetBIOS name types describe the functionality of the registration.
Unique (U): The name may have only one IP address assigned to it. On a network device multiple occurrences of a single name may appear to be registered. The suffix may be the only unique character in the name.
Group (G): A normal group; the single name may exist with many IP addresses. WINS responds to a name query on a group name with the limited broadcast address (255.255.255.255). Because routers block the transmission of these addresses, the Internet Group was designed to service communications between subnets.
Multihomed (M): The name is unique, but due to multiple network interfaces on the same computer this configuration is necessary to permit the registration. The maximum number of addresses is 25.
Internet Group (I): This is a special configuration of the group name used to manage Windows NT Domain names.
Domain Name (D): New in Windows NT 4.0.
For additional information, please see the following article in the Microsoft Knowledge Base:
ARTICLE-ID: 119495 TITLE : List of Names Registered with WINS Service
ARTICLE-ID: 154608 TITLE : NETBIOS Node Status Query Returns First Instance of Unique Name