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Q174904: Information about TCP/IP Port Assignments

Article: Q174904
Product(s): Windows for Workgroups and Windows NT Networking Issues
Version(s): 2.2c,2000,3.0,3.1,3.11,3.5,3.51,4.0
Operating System(s): 
Keyword(s): kbnetwork win95 win98
Last Modified: 13-AUG-2002

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The information in this article applies to:

- Microsoft Windows NT Server versions 3.1, 3.5, 3.51, 4.0 
- Microsoft Windows NT Workstation versions 3.1, 3.5, 3.51, 4.0 
- Microsoft Windows NT Advanced Server, version 3.1 
- Microsoft Windows 2000 Professional 
- Microsoft Windows 2000 Server 
- Microsoft Windows 2000 Advanced Server 
- Microsoft Windows 2000 Datacenter Server 
- Microsoft Windows for Workgroups version 3.11 
- Microsoft Windows Millennium Edition 
- Microsoft Windows 98 
- Microsoft Windows 95 
- Microsoft LAN Manager, version 2.2c 
- Microsoft Network Client for MS-DOS version 3.0 
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SUMMARY
=======

This article provides information about port assignments for various TCP/IP
ports. This was previously documented in RFC 1700.

The assignments are now listed as living documents, constantly updated and
revised when new information is available and new assignments are made. The
specific location of the port numbers list is now available at the following Web
site:

  http://www.iana.org/assignments/port-numbers

MORE INFORMATION
================

PORT NUMBERS
------------

The port numbers are divided into three ranges: the Well Known Ports, the
Registered Ports, and the Dynamic and/or Private Ports.

- The Well Known Ports are those from 0 through 1023.

- The Registered Ports are those from 1024 through 49151.

- The Dynamic and/or Private Ports are those from 49152 through 65535.

WELL KNOWN PORT NUMBERS
-----------------------

The Well Known Ports are assigned by the IANA and on most systems can only be
used by system (or root) processes or by programs executed by privileged users.
Ports are used in the TCP [RFC793] to name the ends of logical connections which
carry long term conversations. For the purpose of providing services to unknown
callers, a service contact port is defined.

The contact port is sometimes called the "well-known port" .To the extent
possible, these same port assignments are used with the UDP [RFC768]. The
assigned ports use a small portion of the possible port numbers. For many years
the assigned ports were in the range 0-255. Recently, the range for assigned
ports managed by the IANA has been expanded to the range 0-1023.

REGISTERED PORT NUMBERS
-----------------------

The Registered Ports are listed by the IANA and on most systems can be used by
ordinary user processes or programs executed by ordinary users. Ports are used
in the TCP [RFC793] to name the ends of logical connections which carry long
term conversations. For the purpose of providing services to unknown callers, a
service contact port is defined.

The IANA registers uses of these ports as a convenience to the community. To the
extent possible, these same port assignments are used with the UDP [RFC768]. The
Registered Ports are in the range 1024-49151.

For information about specific TCP/IP port assignments, see RFC 1700 on the
Information Sciences Institute Web site at the following location:

  ftp://ftp.isi.edu/in-notes/rfc1700.txt

Microsoft provides third-party contact information to help you find technical
support. This contact information may change without notice. Microsoft does not
guarantee the accuracy of this third-party contact information.

Additional query words: tcpip

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Keywords          : kbnetwork win95 win98 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbwin2000AdvServ kbwin2000AdvServSearch kbwin2000DataServ kbwin2000DataServSearch kbwin2000Serv kbWinNTW310 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS350 kbWinNTS310 kbWinNTAdvSerSearch kbWinNTAdvServ310 kbwin2000ServSearch kbwin2000Search kbwin2000ProSearch kbwin2000Pro kbWinNTS351search kbWinNTS350search kbWinNTS310search kbWinMEsearch kbAudDeveloper kbWin95search kbWin98search kbWinNT310Search kbWinNTW310Search kbZNotKeyword kbLanManSearch kbWFWSearch kbWinAdvServSearch kbWinDataServSearch kbZNotKeyword3 kbNetworkClientSearch kbWFW311 kbWin98 kbWinME kbLanMan220c kbNetworkClient300DOS
Version           : :2.2c,2000,3.0,3.1,3.11,3.5,3.51,4.0
Issue type        : kbinfo

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