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Common Ports List with Security Notes

Search 44 common TCP and UDP ports with the service that uses them and the key security note for each, from SSH and RDP to SMB, databases and OT protocols like Modbus and DNP3.

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Port reference

๐Ÿ”’ Runs locally in your browser. Nothing you enter is uploaded.

How to use it

  1. Search by port number, protocol or service name.
  2. Read the security note.
  3. Use it to review firewall rules and exposure.

Frequently asked questions

Which ports should never face the internet?

SMB (445), RDP (3389) without a gateway, databases (1433, 3306, 5432, 27017), Redis (6379) and OT protocols.

Is port 443 always safe?

It's encrypted transport, not a guarantee. The service behind it still needs patching and hardening.

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