[Network +] Port Designations, well known port numbers and common applications

[Mark]

[Network +] Port Designations, well known port numbers and common applications

This is a very basic over view of the essential, need to know, port numbers and what applications use them.

There are 65,535 ports available. Ports are divided into three groups with some being used more than others.

Well-known ports
Well-known ports go from 0 to 1023.

Registered ports
Registered ports range from 1024 to 49151

Dynamic or private ports
Dynamic or private ports range from 49152 to 65535


Below, I've constructed a list of the commonly used well-known ports and applications that use those ports as well as what protocol they use, TCP, UDP or both.

You should familiarise yourself with the below port numbers as they're common knowledge and you will be tested on them.


Essential

Port number / Application / Protocol

20 - FTP (Data) - TCP
21 - FTP (Control) - TCP (If you are asked what port FTP uses, go with 21)
22 - SSH - TCP
23 - Telnet - TCP
25 - SMTP - TCP
53 - DNS - UDP
67 - DHCP
69 - TFTP - UDP
80 - HTTP
110 - POP3 - TCP
123 - NTP - TCP
143 - IMAPv4 - TCP
161 - SNMP
443 - HTTPS


Recommended that you know

Port number / Application / Protocol

15 - Netstat
42 - WINS
43 - WHOIS
119 - NNTP
139 - NetBIOS
389 - LDAP
465 - SMTP secure
546 - DHCPv6 client
547 - DHCPv6 server
990 - FTP secure
993 - IMAP secure
995 - POP3 secure
1433 - Microsoft SQL
3389 - Remote Desktop Protocol
5800 - VNC HTTP
5900 - VNC
8080 - Web servers


Like I said this is a very basic overview just stating what runs on the very common ports, if you don't know what any acronyms stand for or if you have any questions etc either google it or post.

Related thread(s)
[Network +] Common networking protocols and the TCP/IP suite