Common port lookup
Search well-known TCP and UDP port numbers and the services that use them.
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| Port | Protocol | Service | Notes |
|---|
Ports in one minute
An IP address gets traffic to the right device; a port number gets it to the right application on that device. Well-known ports run from 0 to 1023 and are reserved for standard services such as SSH (22), DNS (53) and HTTPS (443).
When you write firewall rules, allow only the ports a service really needs, and never expose management ports such as RDP (3389), SMB (445) or Telnet (23) directly to the internet.