Q136403: Description of UDP Ports
Article: Q136403
Product(s): Windows for Workgroups and Windows NT Networking Issues
Version(s): 3.1,3.11,3.11a,3.11b,3.5,3.51
Operating System(s):
Keyword(s):
Last Modified: 19-MAR-2002
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The information in this article applies to:
- Microsoft Windows NT Server versions 3.1, 3.5, 3.51
- Microsoft Windows NT Workstation versions 3.1, 3.5, 3.51
- Microsoft Windows NT Advanced Server, version 3.1
- Microsoft TCP/IP-32 for Windows for Workgroups, versions 3.11, 3.11a, 3.11b
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SUMMARY
=======
The User Datagram Protocol is an unreliable, connectionless oriented protocol
that uses an IP address for the destination host and a port number to identify
the destination application.
The UDP port number is distinct from any physical port on a computer such as a
COM port or an I/O port address. The UDP port is a 16-bit address that exists
only for the purpose of passing certain types of datagram information to the
correct location above the transport layer of the protocol stack.
MORE INFORMATION
================
UDP ports are not the same as TCP ports, though TCP and UDP may use the same
port number in certain instances. The UDP ports can receive more than one
message at a time, and they are identified by "well known" port numbers. The
following is a listing of some of the more common "well known" UDP ports:
Port Keyword Description
---- ----------- ------------------------------
15 NETSTAT What is the network status
53 DOMAIN Domain Name Server
69 TFTP Trivial File Transfer Protocol
137 NETBIOS-NS NetBIOS name service
138 NETBIOS-DGM NetBIOS datagram service
161 SNMP SNMP network monitor
The UDP specification is defined in RFC 768.
Note: The NETBIOS-NS (NetBIOS name service) port value can be configured to
accommodate products from specific vendors. The Registry parameter that controls
this value is NameServerPort.
For additional information on the NameServerPort parameter, please see the
following article(s) in the Microsoft Knowledge Base:
Q120642 TCP/IP and NBT Configuration Parameters for Windows 2000 or Windows
NT
REFERENCES
==========
"Inter-Networking with Microsoft TCP/IP Using Microsoft Windows NT,
Participant's Workbook," P/N 4275A, Appendix A, page 222.
"TCP/IP Illustrated, Volume 1, The Protocols," W. Richard Stevens, pp 6,7,12,13,
Addison-Wesley, 1994.
Additional query words: ppp endpoint connection
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Keywords :
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Version : :3.1,3.11,3.11a,3.11b,3.5,3.51
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