Port Reference
Searchable database of common network ports. Find port numbers, service names, protocols, descriptions, and security recommendations.
How to Use the Port Reference
- Browse the list of common network ports sorted by port number.
- Use the search field to filter by port number, service name, or protocol.
- Click on any port to expand detailed description and security notes.
- Review security recommendations for ports you are exposing on your network.
About Port Reference
Network ports are logical endpoints for communication in computer networking. Port numbers range from 0 to 65535 and are divided into three ranges: well-known ports (0-1023) assigned by IANA for standard services, registered ports (1024-49151) for specific applications, and dynamic/private ports (49152-65535) for temporary connections. Understanding which ports are open and what services they run is fundamental to network security. Each port entry in this reference includes the port number, service name, protocol (TCP/UDP), a description of the service, and security notes with recommendations. This knowledge is essential for firewall configuration, penetration testing, and network hardening.
Frequently Asked Questions
TCP (Transmission Control Protocol) provides reliable, ordered delivery with error checking and is used for web traffic, email, and file transfers. UDP (User Datagram Protocol) is faster but unreliable, used for DNS queries, streaming, and gaming.
At minimum, block ports commonly targeted by attackers: 23 (Telnet), 135-139 (NetBIOS), 445 (SMB), and any database ports (3306, 5432, 27017) from external access. Only expose ports needed for your specific services.
Yes, any service can run on any port. For example, web servers can use port 8080 instead of 80. However, well-known ports are standard conventions that clients expect by default.