Port Number Reference
TCP, UDP, and SCTP all use port numbers to identify the logical communications between hosts. The combination of a port and IP address identifies a TCP/UDP/SCTP Endpoint, and the endpoint pairs on either end of a "connection" make up a TCP/UDP/SCTP Conversation.
As the underlying IP protocol can "only" transfer data between two IP hosts, it's often desired to transfer TCP/UDP data from more than one application between two IP hosts.
The concept of a TCP/UDP port is to provide several logical channels between the same IP hosts. When sending a packet, TCP/UDP multiplexes the data from separate applications over one IP "host to host transfer". While receiving, TCP/UDP demultiplexes the IP packets again, providing the received data to the applications interested in.
The addressing of this multiplexing/demultiplexing is done using the ports.
Port numbers are unsigned 16-bit integers, ranging from 0 to 65535. The IANA list of assigned port numbers has divided ports into three ranges (RFC 6335):
- 0 through 1023: Well Known Ports
- 1024 through 49151: Registered Ports
- 49152 through 65535: Dynamic or Private Ports
o the System Ports, also known as the Well Known Ports, from 0-1023
(assigned by IANA)
o the User Ports, also known as the Registered Ports, from 1024-
49151 (assigned by IANA)
o the Dynamic Ports, also known as the Private or Ephemeral Ports,
from 49152-65535 (never assigned)Ports 1024 and above are also referred to as ephemeral ports.
Ports are officially registered with the IANA. Unofficial lists are maintained by many people, including the following:
A local list is maintained below:
Discussion
Imported from https://wiki.wireshark.org/PortReference on 2020-08-11 23:18:00 UTC