Port Number Lookup — Common TCP/UDP Service & Protocol Database
Searchable reference for 80+ well-known TCP and UDP ports. Look up any port number or service name to see the official protocol, service description, port range (well-known/registered), and security recommendations for risky ports.
How to Use Port Number Lookup — Common TCP/UDP Service & Protocol Database
How to Use the Port Number Reference:
Search by Port Number: Type a port number in the search box to instantly filter the table. Entering 22 shows SSH; entering 3 shows all ports starting with 3 (3000, 3306, 3389, etc.), letting you explore related ports quickly.
Search by Service Name: Type a service name or keyword to find matching ports. Searching "postgres" returns port 5432, "redis" returns 6379, and "vpn" shows OpenVPN, PPTP, WireGuard, and IPsec entries. Search is case-insensitive and matches service names and descriptions.
Filter by Category: Click any category pill (Web, Database, Remote, Email, Messaging, etc.) to narrow the table to a specific group. Combine a category filter with a text search for precise lookups, such as all Database ports containing "sql".
Read Security Notes: Rows with an amber warning icon (⚠) have associated security recommendations. Click the row to expand and read the note. Security notes explain known risks and recommended mitigations — useful when configuring firewalls or auditing open ports.
Browse the Full Table: Leave the search empty to see all 80+ ports sorted by port number. The table columns show: port number, protocol (TCP/UDP), service name, category, and description. Scroll horizontally on small screens.
Clear Filters: Click the Clear button or remove your search text to reset to the full port list.
Use for Firewall Rules: Use the port, protocol, and service columns to write accurate firewall rules. For example, allowing SSH requires TCP port 22; DNS requires both TCP and UDP on port 53 (TCP for zone transfers, UDP for queries).
Common Use Cases:
- Firewall configuration: Verify which protocol and port a service uses before writing allow/deny rules.
- Security audits: Review which open ports are high-risk and check the security notes for remediation steps.
- DevOps setup: Quickly confirm database, message broker, and monitoring port numbers when configuring services.
- Kubernetes networking: Look up control-plane and node ports (6443, 10250, 2379, 2380) for network policy configuration.
- Incident response: Identify what service is behind an unfamiliar port seen in logs or a port scan.
- Study and certification prep: Reference for CCNA, CompTIA Network+, and Security+ exam preparation.
- Documentation: Confirm correct port numbers when writing runbooks or architecture diagrams.
Tips and Best Practices:
- Port 22 (SSH) is the safest remote access option — prefer it over Telnet (23) or unencrypted RDP.
- Always enable authentication on databases (MongoDB, Redis, Elasticsearch) even on internal networks.
- Use LDAPS (636) instead of LDAP (389) to prevent credential interception.
- Disable Docker's insecure API port (2375) — use the TLS port (2376) with client certificates.
- WireGuard (51820) is the recommended modern VPN — simpler and more secure than OpenVPN or PPTP.
- etcd (2379) holds all Kubernetes secrets — it must never be exposed outside the control plane.
Frequently Asked Questions
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