List of TCP / IP-based network services

This is a list of the most important protocols and services based on TCP / IP for the Internet and local computer networks ( LANs ). The individual services are classified according to their purpose or area of responsibility.

A single service is listed with the following data:

Number of the TCP (or UDP ) port on which the service works in the standard setting
Abbreviation of the service
Full name of the service
Explanation

Administrative logs

43	Whois	Who is	Provides administrative and technical information about a domain and its owner.
53 (UDP / TCP)	DNS	Domain Name System	Resolves host names on the Internet into IP addresses .
67 + 68 (UDP)	BOOTP	Bootstrap Protocol	Enables computers without a hard drive to be booted over the network.
546 + 547 (UDP)	DHCP	Dynamic Host Configuration Protocol	Provides a computer with a dynamically assigned IP address and other network-relevant data.
1701 (UDP / TCP)	L2TP	Layer 2 tunneling protocol	Allows you to establish a VPN connection.

File transfer

20 + 21	FTP	File Transfer Protocol	Used to exchange files (in both directions) with an FTP server.
22nd	SFTP	SSH File Transfer Protocol	Used for the encrypted exchange (in both directions) of files with an SSH & FTP server.
69 (UDP)	TFTP	Trivial File Transfer Protocol	Slimmed down version of FTP (see above).
989 + 990	FTPS	File Transfer Protocol over TLS / SSL	Variant of FTP (see above) that sends and receives data via an encrypted channel.

Database access

1352	Lotus Notes	Lotus Notes / Domino	Used for access with Lotus Notes clients to the Lotus Domino server
1433 + 1434	MS-SQL	Microsoft SQL Server	Used to access Microsoft SQL Server via query and management software .
1521	OracleNet	Oracle Net	Used to access Oracle database servers via query and management software .
3306	MySQL	MySQL server	Used to access MySQL database servers via query and management software.
3050	gds_db	Firebird SQL Server	Used to access Firebird database servers via query and management software.
3050	gds_db	Interbase SQL Server	Used to access Interbase database servers via query and management software.
5432	PostgreSQL	PostgreSQL server	Used to access PostgreSQL database servers via query and management software.

e-mail

25th	SMTP	Simple Mail Transfer Protocol	Sending e-mails via mail server .
110	POP3	Post Office Protocol ver. 3	Collection of emails from a mail server.
143	IMAP	Internet Message Access Protocol	Access to emails stored on a mail server.
465	SMTPS	Simple Mail Transfer Protocol over TLS / SSL	Variant of SMTP (see above) that uses an encrypted channel ( SSL ) to the mail server. (outdated)
587	SMTP	Simple Mail Transfer Protocol	SMTP (see above) for customer email programs . Enables encrypted transmission and identification of the sender.
993	IMAPS	Internet Message Access Protocol over TLS / SSL	Variant of IMAP (see above), which uses an encrypted channel (SSL) to the mail server.
995	POP3S	Post Office Protocol ver. 3 over TLS / SSL	Variant of POP3 (see above), which downloads mails from the mail server via an encrypted channel (SSL).

Remote computing

22nd	SSH	Secure Shell	Allows direct access to the operating system shell of another computer via an encrypted channel.
23	Telnet	Telnet	Allows direct access to the operating system shell of another computer. The transmitted data is not encrypted and the user is authenticated with a user name and password (in clear text).
24	RLogin	Remote login	Works in a similar way to Telnet (see above), but the authentication can alternatively also be carried out using the IP address and the source port of the accessing computer.
3389	RDP	Microsoft Remote Desktop	Display and control of the screen content (desktop) of remote computers.
5900	VNC	Remote desktop	Display and control of the screen content (desktop) of remote computers.
6000	X	X Window Server	Communication between the application and the graphic display server under most Unices, enables applications to be easily displayed on another computer

Usenet

119	NNTP	Network News Transfer Protocol	Used to access newsgroups via a news server.
563	NNTPS	Network News Transfer Protocol over TLS / SSL	Variant of NNTP (see above), accesses newsgroups via an encrypted channel.

WWW

80	HTTP	Hypertext Transfer Protocol	Used to download files (mostly HTML documents) from a web server.
443	HTTPS	Hypertext Transfer Protocol over TLS / SSL	Variant of HTTP (see above) that downloads files via an encrypted channel.

Time services

123 (UDP)

NTP

Network Time Protocol

Downloads the current time from an NTP server (which is usually connected to a radio clock or atomic clock ).

Web links