Appendix C. Port Numbers

This appendix lists the assigned port numbers from the Internet Assigned Numbers Authority (IANA). For a more complete list, go to http://www.isi.edu/in-notes/iana/assignments/port-numbers.

The port numbers are divided into three ranges, which are described in Table C-1:

  • The well-known ports are those in the range 0 through 1023.

  • The registered ports are those in the range 1024 through 49151.

  • The dynamic or private ports are those in the range 49152 through 65535.

Table C-1. Port Assignments

Keyword

Decimal

Description

ssh

22/tcp

SSH Remote Login Protocol

ssh

22/udp

SSH Remote Login Protocol

tacacs

49/tcp

Login Host Protocol (TACACS)

tacacs

49/udp

Login Host Protocol (TACACS)

domain

53/tcp

Domain Name Server

domain

53/udp

Domain Name Server

tacacs-ds ...

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