Port Numbers and Protocols

• In TCP/IP and UDP networks, a port is an endpoint to a logical connection and the way a client program specifies a specific server program on a computer in a network.

• The IANA(Internet Assigned Numbers Authority) is responsible for the global coordination of the DNS root, IP addressing , and other Internet Protocol resources.

Types of Port Numbers:

• The Port Numbers are divided into three ranges. Which are:

• IANA maintains the official list of well known and registered ports.
• Well-known Port numbers are reserved for service and applications.
• Registered Port numbers are assigned to user processes or applications.
• Dynamic or Private Ports are usually assigned dynamically to client applications when initiating a connection.

Important Well-known Ports list:

Port Number	Keyword	Description
1	TCPMUX	TCP Port Service Multiplexer
5	RJE	Remote Job Entry
7	ECHO	Echo
18	MSP	Message Send Protocol
20	FTP-Data	File Transfer Protocol-Data
21	FTP-Control	File Transfer Protocol-Control
22	SSH	SSH Remote Login Protocol
23	Telnet	Telnet
25	SMTP	Simple Mail Transfer Protocol
37	Time	Time
42	Name Server	Host Name Server
43	Nick Name	Who Is
49	Login	Login Host Protocol
53	DNS	Domain Name Server
69	TFTP	Trivial File Transfer Protocol
79	Finger	Finger
80	HTTP	World Wide Wed HTTP
93	DCP	Device Control Protool
108	SNAGAS	SNA Gateway Access Server
109	POP2	Post Office Protocol Version 2
110	POP3	Post Office Protocol Version 3
115	SFTP	Simple File Transfer Protocol
118	SQLSERV	SQL Services
119	NNTP	Newsgroup
123	NTP	Network Time Protocol
129	PSWGEN	Password Generator Protocol
156	SQLSRV	SQL Server
179	BGP	Border Gateway Protocol
190	GACP	Gateway Access Control Protocol
194	IRC	Internet Relay Chat
197	DLS	Directory Location Service
443	HTTPS	HTTP Protocol over TLS/SSL
444	SNPP	Simple Network Paging Protocol
546	DHCP Client	Dynamic Host Configuration Protocol Client
547	Dhcp Server	Dynamic Host Configuration Protocol Server
631	IPP	Internet Printing Protocol