ISC2 CC Network Security Practice Question
A technician is configuring a firewall to allow secure web traffic. Which port and protocol should be permitted?
⚠ Common exam trap
The trap is the UDP 443 distractor — candidates who know HTTP/3 uses QUIC may pick it, but the standard, expected answer for 'secure web traffic' is TCP 443.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
TCP port 443
Secure web traffic uses HTTPS, which by default runs over TCP port 443. The question specifies 'secure web traffic,' so the correct protocol/port pairing is TCP 443. HTTPS encrypts HTTP using TLS, protecting confidentiality and integrity of web communications.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
UDP port 443
Why it's wrong here
HTTPS runs over TCP, not UDP; UDP port 443 is used by HTTP/3 and QUIC, which many firewalls and legacy clients do not treat as the standard secure web channel. It is tempting because port 443 is the recognised HTTPS port, and QUIC genuinely uses UDP 443 where modern browsers negotiate it.
- ✗
TCP port 80
Why it's wrong here
Port 80 carries unencrypted HTTP, so permitting it exposes web traffic to interception and tampering, failing the secure-transport requirement. It is tempting because port 80 is the default for ordinary web browsing and is often enabled for redirects to HTTPS, which is legitimate when the redirect itself is the intended service.
- ✓
TCP port 443
Why this is correct
HTTPS traffic uses TCP port 443, where TLS encapsulates HTTP. Permitting TCP 443 satisfies the secure web traffic requirement; port 80 carries unencrypted HTTP, and UDP 443 is used by HTTP/3 rather than standard secure browsing.
- ✗
TCP port 22
Why it's wrong here
Port 22 carries SSH for remote administration, not HTTPS web traffic, so permitting it opens management access rather than serving the requested secure web service. It is tempting because SSH is itself encrypted and commonly used by technicians for secure remote sessions, making it the correct choice when the requirement is secure device administration.
Go deeper
Related to this question
Learn chapter
Secure Network Architecture and Design
Key term
Firewall
A firewall is a network security system that monitors and controls incoming and outgoing traffic based on predetermined security rules to protect trusted internal networks from untrusted external networks.
Key term
Confidentiality
Confidentiality means keeping sensitive information secret and accessible only to authorized people or systems.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official ISC2 exam blueprint
This CC practice question is part of Courseiva's free ISC2 certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CC exam.