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Information about TCP/IP port assignments
Article ID: 174904 - View products that this article applies to.
This article was previously published under Q174904
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, regularly 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:
PORT NUMBERSThe port numbers are divided into three ranges: the Well Known Ports, the Registered Ports, and the Dynamic and/or Private Ports.
WELL KNOWN PORT NUMBERSThe 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 NUMBERSThe 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.txtMicrosoft 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.
Article ID: 174904 - Last Review: March 27, 2007 - Revision: 3.4