TCP & UDP Port Reference Database
Searchable database of well-known TCP/UDP network ports (HTTP, SSH, MySQL, WireGuard, Redis) with security advisories.
TCP & UDP Network Port Directory & Transport Layer Security
Searchable directory of well-known, registered, and dynamic Layer-4 network ports with security advisories.
In computer networking, a port is a virtual communication endpoint defined in the Transport Layer (Layer 4) protocols: Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). Ports range from 0 to 65535, enabling operating systems to multiplex network traffic across hundreds of concurrent applications.
How It Works & Underlying Architecture
The Internet Assigned Numbers Authority (IANA) divides port numbers into three ranges: Well-Known Ports (0-1023) reserved for system services like HTTP (80), HTTPS (443), and SSH (22); Registered Ports (1024-49151) used by user processes and databases like MySQL (3306) and Redis (6379); and Dynamic/Private Ports (49152-65535) used for ephemeral client connections. Our database provides instant lookup, security vulnerability notes, and firewall configuration rules.
Technical Specifications & Standards
| Standard | IANA Port Number Registry / RFC 6335 |
| Port Range | 0 - 65,535 (16-bit unsigned integer) |
| Protocols | TCP (Connection-Oriented), UDP (Connectionless) |
Real-World Engineering & Creative Use Cases
- Firewall Hardening: Determining which inbound ports must be blocked on production servers.
- Penetration Testing & Port Scanning: Identifying services discovered during Nmap network reconnaissance.
- DevOps Container Routing: Mapping host ports to internal container ports in Docker and Kubernetes.
Frequently Asked Questions (FAQ)
What is the difference between TCP and UDP?
TCP provides reliable, ordered, error-checked packet delivery with a 3-way handshake. UDP is connectionless and lightweight with lower latency, ideal for gaming, DNS, and real-time streaming.
Why should default database ports (3306, 5432, 27017) never be exposed to the public internet?
Exposing default database ports invites automated botnet brute-force attacks and vulnerability exploits. Production databases should reside in private subnets accessible only via VPN or SSH tunnels.