Find the service.
Confirm its configured port.

A port number.
Not a firewall plan.

Confirm the actual listening service, transport, source addresses and direction before changing policy.

A curated common-use view

This list selects common operational transports; it is not a complete IANA registry or every transport registered for a service. A TCP and UDP port with the same number are separate endpoints. Searching digits matches an exact port number.

Ports can change

Services can use custom ports. SQL Server named instances can use dynamic ports; SQL Browser discovery does not replace the engine’s configured TCP port. Opening a listed port does not configure the service, validate encryption or prove access.

Traffic does not identify a service

Any application may use a port different from its conventional assignment. A registered port does not establish that traffic is legitimate or secure. This reference generates no firewall rules.