Quick Answer
The correct answer is HTTPS and SSH, as the access control list interpretation firewall configuration shown permits TCP ports 443 and 22 from any source to host 10.1.1.100. This is because the ACL is applied inbound on the internet-facing interface, meaning it inspects all incoming traffic and only allows packets destined for those specific services to reach the host. On the Certified Information Systems Auditor CISA exam, this tests your ability to read and interpret an ACL rule set in a network security context, a common task for auditors evaluating firewall effectiveness. A frequent trap is misreading the direction of the ACL or confusing permitted ports with denied ones; remember that the ACL explicitly allows only the listed ports. Memory tip: think "HTTPS and SSH are the two S's of secure remote access" to recall that port 443 and port 22 are the only services allowed through.
This CISA practice question tests your understanding of protection of information assets. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
access-list 100 permit tcp any host 10.1.1.100 eq 443 access-list 100 permit tcp any host 10.1.1.100 eq 22 access-list 100 deny ip any any
Refer to the exhibit. Which of the following services is accessible from the internet to host 10.1.1.100?
access-list 100 permit tcp any host 10.1.1.100 eq 443 access-list 100 permit tcp any host 10.1.1.100 eq 22 access-list 100 deny ip any any
HTTP only
Why wrong: HTTP (port 80) is not permitted by the ACL.
Telnet only
Why wrong: Telnet (port 23) is not permitted.
HTTPS and SSH
Ports 443 (HTTPS) and 22 (SSH) are explicitly permitted.
FTP only
Why wrong: FTP (port 21) is not permitted.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
HTTPS and SSH
The exhibit shows an access control list (ACL) permitting TCP ports 443 (HTTPS) and 22 (SSH) from any source to host 10.1.1.100. Since the ACL is applied inbound on the internet-facing interface, only HTTPS and SSH traffic are allowed through to that host. Therefore, option C is correct.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Common exam traps
The trap here is that candidates often confuse HTTP with HTTPS or Telnet with SSH, assuming that if one is allowed, the other must also be allowed, but the ACL explicitly permits only the specific port numbers listed.
Detailed technical explanation
The ACL uses standard TCP port numbers to filter traffic: HTTPS (443) and SSH (22) are explicitly permitted, while all other ports are implicitly denied by the default deny-all at the end of the ACL. In real-world scenarios, this configuration is common for securing a management host that requires encrypted remote administration (SSH) and web-based GUI access (HTTPS), while blocking unencrypted or legacy protocols like HTTP, Telnet, and FTP.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A security administrator must allow nursing staff to reach a patient records server while blocking access from the guest Wi-Fi VLAN. After applying an extended ACL, traffic is still blocked from nursing workstations. The ACL was applied outbound instead of inbound on the wrong interface. Questions like this test ACL direction and placement rules.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Protection of Information Assets — study guide chapter
Learn the concepts, then practise the questions
Protection of Information Assets practice questions
Targeted practice on this topic area only
All CISA questions
509 questions across all exam domains
Certified Information Systems Auditor CISA study guide
Full concept coverage aligned to exam objectives
CISA practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise CISA questions linked to Governance and Management of IT.
Practise CISA questions linked to Information Systems Acquisition, Development and Implementation.
Practise CISA questions linked to Information Systems Operations and Business Resilience.
Practise CISA questions linked to Protection of Information Assets.
Practise CISA questions linked to Information System Auditing Process.
Practise CISA questions linked to CISA fundamentals.
Practise CISA questions linked to CISA scenario.
Practise CISA questions linked to CISA troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Protection of Information Assets — This question tests Protection of Information Assets — Read the scenario before looking for a memorised answer..
The correct answer is: HTTPS and SSH — The exhibit shows an access control list (ACL) permitting TCP ports 443 (HTTPS) and 22 (SSH) from any source to host 10.1.1.100. Since the ACL is applied inbound on the internet-facing interface, only HTTPS and SSH traffic are allowed through to that host. Therefore, option C is correct.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 25, 2026
This CISA practice question is part of Courseiva's free ISACA 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 CISA exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.