- A
22
Port 22 is the default SSH port, used for secure remote administration.
- B
23
Why wrong: Port 23 is Telnet, which is unencrypted and not secure.
- C
161
Why wrong: Port 161 is SNMP, used for network management, not remote administration.
- D
443
Why wrong: Port 443 is HTTPS, used for web-based management, not SSH.
Question 243 of 1,020
SSH Default Port 22 for CompTIA A+ 220-1201
This 220-1201 practice question tests your understanding of tcp & udp ports. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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.
A network administrator needs to allow secure remote administration of a router using SSH. The router is configured to use the default SSH port. Which port must be opened on the firewall?
Quick Answer
The answer is port 22. SSH, or Secure Shell, uses TCP port 22 by default to establish an encrypted tunnel for remote command-line administration, ensuring that all data—including login credentials—is protected from eavesdropping. On the CompTIA A+ Core 1 220-1201 exam, this question tests your ability to distinguish secure protocols from insecure alternatives like Telnet (port 23) and to recall default port numbers for common services. A frequent trap is confusing SSH with SSL/TLS (port 443) or assuming SSH uses port 22 only for file transfers, when in fact it is primarily for secure shell access. Remember the mnemonic: “Secure Shell sits on 22” to lock in the default.
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
✓
22
SSH (Secure Shell) operates on TCP port 22 by default. To allow secure remote administration of the router, the firewall must permit inbound TCP traffic on port 22. This enables encrypted management sessions, unlike Telnet which uses unencrypted port 23.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
22
Why this is correct
Port 22 is the default SSH port, used for secure remote administration.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
23
Why it's wrong here
Port 23 is Telnet, which is unencrypted and not secure.
- ✗
161
Why it's wrong here
Port 161 is SNMP, used for network management, not remote administration.
- ✗
443
Common exam traps
Common exam trap: answer the scenario, not the keyword
In the CompTIA A+ exam, candidates often confuse SSH (port 22) with Telnet (port 23). Since the question specifies 'secure' remote administration, the correct answer is SSH port 22, not Telnet's unencrypted port 23.
Detailed technical explanation
How to think about this question
SSH uses TCP port 22 as defined in RFC 4251. The protocol establishes an encrypted tunnel using asymmetric key exchange (e.g., Diffie-Hellman) and symmetric encryption (e.g., AES) to protect session data. In real-world deployments, administrators often change the default SSH port to a non-standard value to reduce automated attack traffic, but the question explicitly states the default port is used.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
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
Got this wrong? Here's your next step.
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FAQ
Questions learners often ask
What does this 220-1201 question test?
TCP & UDP Ports — This question tests TCP & UDP Ports — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: 22 — SSH (Secure Shell) operates on TCP port 22 by default. To allow secure remote administration of the router, the firewall must permit inbound TCP traffic on port 22. This enables encrypted management sessions, unlike Telnet which uses unencrypted port 23.
What should I do if I get this 220-1201 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
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 →
Same concept, more angles
1 more ways this is tested on 220-1201
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A user needs to transfer files securely between two Linux servers over the internet. Which port should be allowed through the firewall for this purpose?
medium- A.21
- ✓ B.22
- C.20
- D.443
Why B: Secure file transfer between Linux servers typically uses SCP (Secure Copy) or SFTP (SSH File Transfer Protocol), both of which operate over SSH. SSH uses TCP port 22 by default, so allowing port 22 through the firewall enables encrypted authentication and data transfer. This is the correct choice because it provides confidentiality and integrity for the file transfer over the internet.
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Last reviewed: Jul 4, 2026
This 220-1201 practice question is part of Courseiva's free CompTIA 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 220-1201 exam.
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