The Most Common Network Ports Explained

The Most Common Network Ports Explained

Every network service communicates through ports. Knowing the most common ports helps administrators secure systems and troubleshoot connectivity issues.

Port 20 & 21 — FTP

Used for File Transfer Protocol.

Port 22 — SSH

Secure remote administration.

Port 25 — SMTP

Email transfer.

Port 53 — DNS

Domain name resolution.

Port 80 — HTTP

Unencrypted web traffic.

Port 443 — HTTPS

Encrypted web traffic using TLS.

Port 110 — POP3

Email retrieval.

Port 143 — IMAP

Modern email synchronization.

Port 3306 — MySQL

Database communication.

Port 3389 — Remote Desktop

Windows Remote Desktop Protocol.

Why Are Ports Important?

Open ports expose services to the network. Unnecessary ports should always be closed to reduce the attack surface.

Conclusion

Knowing common ports is fundamental for network administrators, ethical hackers, and cybersecurity analysts.