A port number is a way to identify a specific process to which the Internet or another network message is to be forwarded when it arrives at a server. For the Transmission Control Protocol and the User Datagram Protocol, a port number is a 16-bit integer that is put in the header appended to a message unit.

Note: Port number 0 is reserved and cannot be used.

List of Well-Known TCP/IP Port Numbers

Below, we take a look at these protocols, provides a basic description of their function, and lists the port numbers that they are commonly associated with.

Protocol Port Number Description
File Transfer Protocol (FTP) 20/21 FTP is one of the most commonly used file transfer protocols on the Internet and within private networks.FTP control is handled on TCP port 21 and its data transfer can use TCP port 20 as well as dynamic ports depending on the specific configuration.
Secure Shell (SSH) 22 SSH is the primary method used to manage network devices securely at the command level. It is typically used as a secure alternative to Telnet which does not support secure connections.
Telnet 23 Telnet is the primary method used to manage network devices at the command level. Unlike SSH which provides a secure connection, Telnet does not, it simply provides a basic unsecured connection. Many lower level network devices support Telnet and not SSH as it required some additional processing.
Simple Mail Transfer Protocol (SMTP) 25 SMTP is used for two primary functions, it is used to transfer mail (email) from source to destination between mail servers and it is used by end users to send an email to a mail system.
Domain Name System (DNS) 53 The DNS is used widely on the public internet and on private networks to translate domain names into IP addresses, typically for network routing.
Dynamic Host Configuration Protocol (DHCP) 67/68 DHCP is used on networks that do not use static IP address assignment. A DHCP server can be set up by an administrator or engineer with a poll of addresses that are available for assignment.When a client device is turned on it can request an IP address from the local DHCP server, if there is an available address in the pool it can be assigned to the device. This assignment is not permanent and expires at a configurable interval; if an address renewal is not requested and the lease expires the address will be put back into the poll for assignment.
Trivial File Transfer Protocol (TFTP) 69 TFTP offers a method of file transfer without the session establishment requirements that FTP uses. Because TFTP uses UDP instead of TCP it has no way of ensuring the file has been properly transferred, the end device must be able to check the file to ensure proper transfer. TFTP is typically used by devices to upgrade software and firmware.
Hypertext Transfer Protocol (HTTP) 80 HTTP is one of the most commonly used protocols on most networks. HTTP is the main protocol that is used by web browsers and is thus used by any client that uses files located on these servers. Its Alternative Port number is 8080.
Post Office Protocol (POP) version 3 110

POP version 3 is one of the two main protocols used to retrieve mail from a server. POP was designed to be very simple by allowing a client to retrieve the complete contents of a server mailbox and then deleting the contents from the server.

Network Time Protocol (NTP) 123 One of the most overlooked protocols is NTP. NTP is used to synchronize the devices on the Internet. Even most modern operating systems support NTP as a basis for keeping an accurate clock. The use of NTP is vital on networking systems as it provides an ability to easily interrelate troubles from one device to another as the clocks are precisely accurate.
Internet Message Access Protocol (IMAP) 143 IMAP version3 is the second of the main protocols used to retrieve mail from a server. While POP has wider support, IMAP supports a wider array of remote mailbox operations which can be helpful to users.
Simple Network Management Protocol (SNMP) 161/162

SNMP is used by network administrators as a method of network management. SNMP has a number of different abilities including the ability to monitor, configure and control network devices. SNMP traps can also be configured on network devices to notify a central server when specific actions are occurring. Typically, these are configured to be used when an alerting condition is happening.

Hypertext Transfer Protocol over SSL/TLS (HTTPS) 443 HTTPS is used in conjunction with HTTP to provide the same services but doing it using a secure connection which is provided by either SSL or TLS.
FTP over TLS/SSL 989/990 Again, just like the previous two entries, FTP over TLS/SSL uses the FTP protocol which is then secured using either SSL or TLS.
Microsoft SQL Server 1443 Microsoft SQL Server is a relational database management system developed by Microsoft. As a database server, it is a software product with the primary function of storing and retrieving data as requested by other software applications which may run either on the same computer or on another computer across a network (including the Internet).
cPanel default port 2082 cPanel is a Linux-based web hosting control panel that provides a graphical interface and automation tools designed to simplify the process of hosting a website. cPanel port number 2082 is the way of establishing an unencrypted connection to the server through HTTP.
cPanel over SSL 2083 cPanel is a Linux-based web hosting control panel that provides a graphical interface and automation tools designed to simplify the process of hosting a website. cPanel port number 2083 is the way of establishing an encrypted connection to the server through HTTP.
cPanel Web Host Manager (default) 2086 Web Host Manager, or WHM, is a powerful program that allows administrative access to the back end of cPanel. WHM port number 2086 is the way of establishing an unencrypted connection to the server through HTTP.
cPanel Web Host Manager (with https) 2087 Web Host Manager(WHM) is a powerful program that allows administrative access to the back end of cPanel. WHM port number 2087 is the way of establishing an encrypted connection to the server through HTTP.
cPanel Webmail 2095 Webmail allows you to access your email accounts through any web browser. This is helpful if you need to check your email but do not have current access to your own computer. Webmail port number 2095 is the way of establishing an encrypted connection to the server through HTTP.
cPanel secure webmail over SSL 2096 Webmail allows you to access your email accounts through any web browser. This is helpful if you need to check your email but do not have current access to your own computer. Webmail port number 2096 is the way of establishing an encrypted connection to the server through HTTP.
DirectAdmin Server Control Panel 2222 DirectAdmin is a graphical web-based web hosting control panel designed to make administration of websites easier. DirectAdmin Server Control Panel port number 2222 is the way of establishing an encrypted connection to the server through HTTP.
MySQL Database Server 3306 MySQL  is an open source relational database management system (RDBMS) and the most widely used open-source client–server model RDBMS. Connection to the server running uses the default port number 3306.
Virtuozzo Power Panel 4643 Virtuozzo is a proprietary system and control panel used to host a VPS. Virtuozzo Power panel is accessible via 4643 port number.
PostgreSQL Database Server 5432 The world’s most advanced open source database and is backed by a vibrant and innovative community with proven customer success.
Plesk Control Panel Port (default) 8880 Plesk is a control panel available on our Windows-based hosting accounts and servers. It lets you easily manage many aspects of your account, including the files, applications, and (for servers) email hosted on your account or server.Plesk Control Panel port number 8880 is the way of establishing an unencrypted connection to the server through HTTP.
Plesk Server Control Panel over SSL 8443 Plesk is a control panel available on our Windows-based hosting accounts and servers. It lets you easily manage many aspects of your account, including the files, applications, and (for servers) email hosted on your account or server.Plesk Control Panel port number 8443 is the way of establishing an encrypted connection to the server through HTTP.
DotNet Panel 9001 DotNetPanel is a unique feature-rich solution for simplifying Windows hosting management operations. It manages multiple servers, has robust, scalable and secure architecture and it’s very simple in use.
DotNet Panel Login 80 DotNet Panel Login port number 80 is the way of establishing a connection to the server through HTTP.
RDP(Remote Desktop Protocol) 4489 Remote Desktop Protocol (RDP) is a proprietary protocol developed by Microsoft, which provides a user with a graphical interface to connect to another computer over a network connection. The user employs RDP client software for this purpose while the other computer must run RDP server software.