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. Some ports have numbers that are preassigned to them by the IANA, and these are known as well-known ports (specified in RFC 1700). Port numbers range from 0 to 65536, but only ports numbers 0 to 1024 are reserved for privileged services and designated as well-known ports. This list of well-known port numbers specifies the port used by the server process as its contact port.

Port Number

Description

1

TCP Port Service Multiplexer (TCPMUX)

5

Remote Job Entry (RJE)

7

ECHO

18

Message Send Protocol (MSP)

20

FTP -- Data

21

FTP -- Control

22

SSH Remote Login Protocol

23

Telnet

25

Simple Mail Transfer Protocol (SMTP)

29

MSG ICP

37

Time

42

Host Name Server (Nameserv)

43

WhoIs

49

Login Host Protocol (Login)

53

Domain Name System (DNS)

69

Trivial File Transfer Protocol (TFTP)

70

Gopher Services

79

Finger

80

HTTP

103

X.400 Standard

108

SNA Gateway Access Server

109

POP2

110

POP3

115

Simple File Transfer Protocol (SFTP)

118

SQL Services

119

Newsgroup (NNTP)

137

NetBIOS Name Service

139

NetBIOS Datagram Service

143

Interim Mail Access Protocol (IMAP)

150

NetBIOS Session Service

156

SQL Server

161

SNMP

179

Border Gateway Protocol (BGP)

190

Gateway Access Control Protocol (GACP)

194

Internet Relay Chat (IRC)

197

Directory Location Service (DLS)

389

Lightweight Directory Access Protocol (LDAP)

396

Novell Netware over IP

443

HTTPS

444

Simple Network Paging Protocol (SNPP)

445

Microsoft-DS

458

Apple QuickTime

546

DHCP Client

547

DHCP Server

563

SNEWS

569

MSN

1080

Socks

For further information, see RFC 1700.