- A
ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048
This configuration correctly creates an ACL permitting the management subnet, applies it to VTY lines with access-class in, restricts transport to SSH, enables local login, creates the user, sets the domain name, and generates RSA keys with 2048-bit modulus.
- B
ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT out transport input ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048
Why wrong: This is incorrect because the access-class is applied out instead of in. The 'in' direction filters incoming connections to the VTY lines; 'out' would filter outgoing connections from the router, which is not the requirement.
- C
ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input telnet ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048
Why wrong: This is incorrect because 'transport input telnet ssh' allows Telnet in addition to SSH. The requirement is to restrict SSH access only; Telnet is insecure and should be disabled.
- D
ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input ssh login local username admin password Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048
Why wrong: This is incorrect because the username command uses 'password' instead of 'secret'. The 'password' keyword stores the password in plaintext (or weakly encrypted), while 'secret' uses strong encryption (MD5 hash). Cisco best practice and security requirements mandate 'secret'.
Quick Answer
The correct configuration to restrict SSH access with ACL on R1 is to create a standard ACL permitting only the 192.168.1.0/24 subnet, then apply it to the VTY lines with the access-class command in the inbound direction. This works because the access-class directive filters incoming Telnet or SSH sessions at the router’s VTY interface, allowing only traffic from the permitted source network while denying all others by default. On the CCNA 200-301 v2 exam, this scenario tests your understanding of how to secure remote management access by combining ACLs with VTY line configuration—a common task in enterprise network security. A frequent trap is forgetting that the access-class must be applied under the VTY lines, not to a physical interface, or confusing it with an ACL applied to an interface for data traffic. Remember the mnemonic: “VTY lines love access-class, interfaces love access-group.”
CCNA Network Services and Security Practice Question
This 200-301 practice question tests your understanding of network services and security. 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.
You are connected to R1 via the console. R1's GigabitEthernet0/0 (192.168.1.1/24) connects to the management network, and GigabitEthernet0/1 (10.0.0.1/30) connects to the core. You need to restrict SSH access to R1 from only the management subnet 192.168.1.0/24. Additionally, SSH should be configured with a domain name 'example.com' and a modulus of 2048 bits. The username 'admin' with password 'Cisco123' should be created for SSH login.
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
ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048
SSH requires RSA keys for encryption. The access-class applies an ACL to incoming VTY connections, allowing only the management subnet. Setting 'transport input ssh' disables less secure protocols like Telnet.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048
Why this is correct
This configuration correctly creates an ACL permitting the management subnet, applies it to VTY lines with access-class in, restricts transport to SSH, enables local login, creates the user, sets the domain name, and generates RSA keys with 2048-bit modulus.
Related concept
CIDR notation defines the prefix length.
- ✗
ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT out transport input ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048
Why it's wrong here
This is incorrect because the access-class is applied out instead of in. The 'in' direction filters incoming connections to the VTY lines; 'out' would filter outgoing connections from the router, which is not the requirement.
- ✗
ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input telnet ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048
- ✗
ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input ssh login local username admin password Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048
Why it's wrong here
This is incorrect because the username command uses 'password' instead of 'secret'. The 'password' keyword stores the password in plaintext (or weakly encrypted), while 'secret' uses strong encryption (MD5 hash). Cisco best practice and security requirements mandate 'secret'.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048Correct answer▾
Why this is correct
This configuration correctly creates an ACL permitting the management subnet, applies it to VTY lines with access-class in, restricts transport to SSH, enables local login, creates the user, sets the domain name, and generates RSA keys with 2048-bit modulus.
✗ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT out transport input ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048Wrong answer — click to see why▾
Why this is wrong here
The access-class must be applied 'in' to restrict incoming SSH sessions; 'out' controls traffic initiated from the router.
Why candidates choose this
Candidates may confuse the direction of access-class, thinking 'out' applies to external connections.
✗ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input telnet ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048Wrong answer — click to see why▾
Why this is wrong here
The transport input command should be 'ssh' only to disable Telnet.
Why candidates choose this
Candidates might think allowing both Telnet and SSH is acceptable, but the question implies only SSH should be allowed.
✗ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input ssh login local username admin password Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048Wrong answer — click to see why▾
Why this is wrong here
The 'secret' keyword should be used for secure password storage; 'password' is less secure.
Why candidates choose this
Candidates may be unaware of the difference between 'password' and 'secret' in the username command.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Trap categories for this question
Keyword trap
This is incorrect because the username command uses 'password' instead of 'secret'. The 'password' keyword stores the password in plaintext (or weakly encrypted), while 'secret' uses strong encryption (MD5 hash). Cisco best practice and security requirements mandate 'secret'.
Command / output trap
This is incorrect because the username command uses 'password' instead of 'secret'. The 'password' keyword stores the password in plaintext (or weakly encrypted), while 'secret' uses strong encryption (MD5 hash). Cisco best practice and security requirements mandate 'secret'.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
- CIDR notation defines the prefix length.
- Block size helps identify subnet boundaries.
- Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
- The required host count determines the smallest suitable subnet.
TExam Day Tips
- Write the block size before choosing the subnet.
- Check whether the question asks for hosts, subnets or a specific address range.
- Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
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.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 200-301 subnetting questions on CIDR, address ranges, and subnet selection.
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FAQ
Questions learners often ask
What does this 200-301 question test?
Network Services and Security — This question tests Network Services and Security — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: ip access-list standard MGMT permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class MGMT in transport input ssh login local username admin secret Cisco123 ip domain-name example.com crypto key generate rsa modulus 2048 — SSH requires RSA keys for encryption. The access-class applies an ACL to incoming VTY connections, allowing only the management subnet. Setting 'transport input ssh' disables less secure protocols like Telnet.
What should I do if I get this 200-301 question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 200-301 subnetting questions on CIDR, address ranges, and subnet selection.
What is the key concept behind this question?
CIDR notation defines the prefix length.
About these practice questions
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Last reviewed: Jun 7, 2026
This 200-301 practice question is part of Courseiva's free Cisco 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 200-301 exam.
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