Ports and common services

Definition and example

Ports and common services is the focus of this lesson. Ports distinguish application services on a host. Common examples include HTTPS on TCP 443, DNS on port 53 and SSH on TCP 22. Practice: Create a short note for ‘Ports and common services’ in a local training document. Apply the idea to a fictional or deliberately provided sample, record what you checked, and note one limitation. Do not use real credentials, private records or systems without written permission. The task asks you to apply that idea in a small example: Which service commonly uses TCP port 443. Before you run the code, predict what should happen. Then Inspect the result produced by the exercise and compare it with your prediction. If the result differs, change one relevant line and run it again. Testing one change at a time makes the cause of a result easier to understand.