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TCP/UDP Port Numbers Overview
Both TCP and UDP use port numbers to identify the ends of logical communication sessions. These numbers
can be used to identify what service(s) are connecting to a specific address and to track network processes
related to those particiular services.
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.
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 byprivileged users. Ports are used in the TCP [RFC793] to name the ends of logicalconnections which carry long term conversations. For the purpose ofproviding services to unknown callers, a service contact port is defined. This list specifies the port used by the server process as its contact port. The contact port is sometimes called the "well-known port".To the extent possible, these same port assignments are used with theUDP [RFC768].
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.
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 byprivileged users. Ports are used in the TCP [RFC793] to name the ends of logicalconnections which carry long term conversations. For the purpose ofproviding services to unknown callers, a service contact port is defined. This list specifies the port used by the server process as its contact port. The contact port is sometimes called the "well-known port".To the extent possible, these same port assignments are used with theUDP [RFC768].