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Well-Known TCP Port Numbers

Only port numbers 0 to 1024 are reserved for privileged services and designated as well-known ports. Well-known ports are specified in RFC 1700.

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 port number identifies what type of port it is. For example, port 80 is used for HTTP traffic. Some ports have numbers that are pre-assigned to them by the IANA, and these are called the "well-known ports" which are specified in RFC 1700.

List of Well-Known Ports

Port numbers range from 0 to 65536, but only port 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


1 TCP Port Service Multiplexer (TCPMUX)
5 Remote Job Entry (RJE)
18 Message Send Protocol (MSP)
20 FTP -- Data
21 FTP -- Control
22 SSH Remote Login Protocol
23 Telnet
25 Simple Mail Transfer Protocol (SMTP)
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
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
444 Simple Network Paging Protocol (SNPP)
445 Microsoft-DS
458 Apple QuickTime
546 DHCP Client
547 DHCP Server
569 MSN
1080 Socks

For further information, see RFC 1700.

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