1.07.1Basic
Connect to a web server using unencrypted standard HTTP.
No port is written in the URL.
Which destination port is used?
× Incorrect
HTTP uses TCP port 80 by default. HTTPS uses TCP port 443.
Detailed explanation
Incorrect53
Incorrect. 53 is DNS.
Correct80
Correct. TCP port 80 is standard HTTP.
Incorrect123
Incorrect. 123/udp is NTP.
Incorrect443
Incorrect. 443/tcp is standard HTTPS.
Try it yourself
An example you can run in a temporary verification environment.
getent services http | sed -n '1p'Expected result
http 80/tcpを示すサービスデータベース行Key points
- HTTP is 80/tcp
- HTTPS is 443/tcp
- A URL can specify another 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-102-950
EnvironmentLinux NSS servicesデータベース / 外部通信なし
Last technical review2026-08-13
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