300-410 Question 212
Select 3A network engineer is troubleshooting issues with SSH access to a router. The router is configured with an access control list (ACL) to restrict SSH access to specific IP addresses. However, users from allowed IP addresses are still unable to connect via SSH. Which of the following could be the cause of the issue?
- A
The ACL is applied to the wrong interface or direction.
- B
The SSH version configured on the router is incompatible with the client.
- C
The vty lines are not configured with the 'login local' command.
- D
The SSH server on the router is disabled.
- E
The ACL is incorrectly permitting all IP addresses.
Show answer and explanation
Correct answers: A, B, D
Explanation
The issue lies in misconfigurations that impact SSH functionality or access restrictions. Applying the ACL to the wrong interface or direction, using an incompatible SSH version, or having the SSH server disabled are all potential causes of the problem. The absence of 'login local' or an ACL permitting all IP addresses would either have no effect or result in unrestricted access, which does not match the scenario.
- A. Correct.
If the ACL is applied to the wrong interface or direction, it may not filter the intended traffic, causing SSH access issues even for allowed IPs.
- B. Correct.
If the SSH version configured on the router is incompatible with the client, the connection will fail regardless of ACL settings.
- C. Incorrect.
The 'login local' command is used for local authentication, but its absence would not directly cause issues with SSH access restricted by an ACL.
- D. Correct.
If the SSH server is disabled on the router, no SSH connections will be allowed, regardless of ACL settings.
- E. Incorrect.
If the ACL incorrectly permits all IP addresses, SSH access would not be restricted. However, this would not cause access issues for allowed IPs.