1.07.1Basic
Connect to a web server with HTTPS without specifying a port in the URL.
The server listens on its standard port.
Which destination port is used?
× Incorrect
HTTPS uses TCP port 443 by default, while unencrypted HTTP uses TCP port 80.
Detailed explanation
Incorrect22
Incorrect. 22/tcp is SSH.
Incorrect53
Incorrect. 53 is DNS.
Incorrect80
Incorrect. 80/tcp is unencrypted HTTP.
Correct443
Correct. TCP port 443 is standard HTTPS.
Try it yourself
An example you can run in a temporary verification environment.
getent services https | sed -n '1p'Expected result
https 443/tcpを示すサービスデータベース行Key points
- HTTPS is 443/tcp
- HTTP is 80/tcp
- A URL can override the port
Notes
- Environment: Linux NSS servicesデータベース / 外部通信なし
- Command output formatting can vary slightly by distribution or tool version.
- Run the example in a temporary directory or process when possible.
Foundation review
Network prefix
The part of an IP address that identifies the network rather than a host.
Transport protocol
TCP and UDP provide different delivery, reliability, and connection semantics.
Service port
A numbered endpoint used to deliver traffic to a network service.
Question IDKL-102-952
EnvironmentLinux NSS servicesデータベース / 外部通信なし
Last technical review2026-08-13
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