🔎 Introduction:
In today’s interconnected world, port numbers are essential for directing network traffic to the right applications. The Internet Assigned Numbers Authority (IANA) manages and assigns these port numbers to ensure standardization and prevent conflicts across the internet.
Port numbers are divided into three categories:
- Well-Known Ports (0–1023): Common services and protocols.
- Registered Ports (1024–49151): Assigned to specific services and software.
- Dynamic/Private Ports (49152–65535): Used by client applications dynamically.
In this guide, we provide an exhaustive list of IANA-certified ports, their associated applications, and information on whether they are used by default.
📊 Table of IANA Certified Ports and Their Usage
⚡ Well-Known Ports (0–1023):
| Port Number | Application | IANA Certified | Default? |
|---|---|---|---|
| 0 | Reserved | Yes | No |
| 20 | FTP Data Transfer | Yes | Yes |
| 21 | FTP Command Control | Yes | Yes |
| 22 | SSH (Secure Shell) | Yes | Yes |
| 23 | Telnet | Yes | Yes |
| 25 | SMTP (Simple Mail Transfer) | Yes | Yes |
| 53 | DNS (Domain Name System) | Yes | Yes |
| 67 | DHCP Server | Yes | Yes |
| 68 | DHCP Client | Yes | Yes |
| 69 | TFTP (Trivial File Transfer) | Yes | Yes |
| 80 | HTTP | Yes | Yes |
| 88 | Kerberos | Yes | Yes |
| 110 | POP3 (Post Office Protocol v3) | Yes | Yes |
| 123 | NTP (Network Time Protocol) | Yes | Yes |
| 135 | RPC (Remote Procedure Call) | Yes | Yes |
| 137 | NetBIOS Name Service | Yes | Yes |
| 138 | NetBIOS Datagram Service | Yes | Yes |
| 139 | NetBIOS Session Service | Yes | Yes |
| 143 | IMAP | Yes | Yes |
| 161 | SNMP | Yes | Yes |
| 162 | SNMP Trap | Yes | Yes |
| 179 | BGP (Border Gateway Protocol) | Yes | Yes |
| 194 | IRC (Internet Relay Chat) | Yes | Yes |
| 443 | HTTPS | Yes | Yes |
| 445 | Microsoft SMB | Yes | Yes |
| 465 | SMTPS (SMTP Secure) | Yes | Yes |
| 514 | Syslog | Yes | Yes |
| 587 | SMTP Mail Submission | Yes | Yes |
| 636 | LDAPS (Secure LDAP) | Yes | Yes |
| 873 | rsync | Yes | Yes |
| 990 | FTPS Data | Yes | Yes |
| 993 | IMAPS (IMAP Secure) | Yes | Yes |
| 995 | POP3S (POP3 Secure) | Yes | Yes |
📡 Registered Ports (1024–49151):
| Port Number | Application | IANA Certified | Default? |
|---|---|---|---|
| 1080 | SOCKS Proxy | Yes | No |
| 1194 | OpenVPN | Yes | Yes |
| 1433 | Microsoft SQL Server | Yes | Yes |
| 1521 | Oracle Database | Yes | Yes |
| 1701 | L2TP (Layer 2 Tunneling Protocol) | Yes | Yes |
| 1723 | PPTP (Point-to-Point Tunneling) | Yes | Yes |
| 1883 | MQTT (Message Queuing Telemetry) | Yes | Yes |
| 2049 | NFS (Network File System) | Yes | Yes |
| 3306 | MySQL Database | Yes | Yes |
| 3389 | RDP (Remote Desktop Protocol) | Yes | Yes |
| 3690 | Subversion (SVN) | Yes | Yes |
| 5432 | PostgreSQL Database | Yes | Yes |
| 6379 | Redis | Yes | Yes |
| 8080 | HTTP Alternative | Yes | No |
| 8443 | HTTPS Alternative | Yes | No |
| 9418 | Git Protocol | Yes | Yes |
🔥 Dynamic/Private Ports (49152–65535):
| Port Number | Application | IANA Certified | Default? |
|---|---|---|---|
| 49152–65535 | Ephemeral Ports (Dynamic) | No | No |
| 50000 | iSCSI Target Administration | Yes | No |
| 50051 | gRPC | Yes | No |
📝 Categories of Port Usage
1. Well-Known Ports (0–1023)
- Reserved for critical system services.
- Used by major protocols such as HTTP, FTP, SMTP, and DNS.
2. Registered Ports (1024–49151)
- Assigned by IANA for specific services and proprietary software.
- Often used by popular services such as databases and VPNs.
3. Dynamic/Private Ports (49152–65535)
- Also known as ephemeral ports.
- Used dynamically by client applications for temporary connections.
⚠️ Port Security Considerations
When configuring a firewall or managing a server, keep the following best practices in mind:
✅ Close unnecessary ports to reduce the attack surface.
✅ Use secure alternatives where available (e.g., use SFTP/FTPS instead of plain FTP).
✅ Monitor open ports regularly to detect unauthorized access.
🎯 Conclusion:
Understanding and managing IANA-certified ports is essential for maintaining network security and ensuring efficient traffic flow. This guide provides a comprehensive look at certified ports and their typical applications. For the most up-to-date and exhaustive list, visit the IANA Port Registry.
By properly configuring your system and monitoring the ports in use, you can significantly enhance the security and efficiency of your network. Happy networking! 🌐
✅ Pro Tip: Bookmark the IANA registry for easy reference and periodic updates to your firewall rules.
