Search TCP / UDP Port Assignment Database

The Port Search tool helps you quickly look up well-known TCP and UDP ports, network services, and protocol assignments. It can be used to find the default port number for a specific service (for example HTTP, HTTPS, SSH, DNS, or SMTP), determine which application commonly uses a particular port, or explore how ports are organized and assigned.

This tool is useful for network administrators, security analysts, system engineers, students, and anyone troubleshooting connectivity or application communication issues.

To use the Port Search tool, simply enter a port number (for example 443, 22, or 3389) or a keyword related to a service or protocol (https, dns, smtp, MySQL, Kerberos, etc.) in the search box and click "Submit". The tool will search through the selected databases of TCP and UDP port assignments and return any matching results, including the service name, port number, protocol type, description, and any relevant notes or references.

The tool also supports wildcard searches using the * character. The wildcard may only appear at the end of the search pattern and can be used with port numbers and text strings.

TCP and UDP ports are logical communication endpoints used by applications and services on IP networks. Ports allow multiple applications and services to share a single IP address while keeping network traffic separated and organized.

A port number is a 16-bit value ranging from 0 to 65535.

A combination of an IP address and a port number is called a socket, and it uniquely identifies a specific service or application running on a host.

TCP and UDP ports are divided into several standard ranges defined by the Internet Assigned Numbers Authority.

These ports are reserved for widely used and standardized services.

They are typically assigned to:

• Core Internet services
• Operating system services
• Infrastructure protocols

Examples:

Registered ports are commonly used by:

• Commercial applications
• Database services
• Enterprise software
• Vendor-specific application

Organizations and software vendors can register ports for specific applications.

Examples:

These ports are typically used temporarily by client systems for outbound connections.

They are commonly used for:

• Client-side communication
• Temporary sessions
• NAT translations
• Dynamic application assignments

Operating systems automatically allocate these ports when applications initiate network connections.