Most Frequently Used TCP Ports With Short Description – Part I

By | July 28, 2011

A port number is communication endpoint with a computer network. TCP stands for Transmission Control Protocol is the suite of communications protocols used for connecting web hosting servers and transmitting data over networks on the Internet. IANA (Internet Assigned Numbers Authority) has assigned specific numbers to these ports, one can access these ports by entering this assigned number in the address bar. This number should be typed after ‘’ in the address bar of browser. Following is the list of few most frequently used TCP ports. The range of port numbers is very large (0 to 65536) but only few of them are reserved for privileged services and designated as well-known ports which are classified in the range from 0 to 1080.

Port No Description
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

Rest of the well-known ports are given in the next post.