300-440 Question 251
Select 2You are configuring a Cisco router to ensure secure remote access for administrators. The requirement is to allow SSH access on the VTY lines while blocking Telnet access. Which of the following commands must be applied to achieve this configuration?
- A
transport input ssh
- B
transport input telnet
- C
transport input ssh telnet
- D
line vty 0 4
- E
enable secret cisco123
Show answer and explanation
Correct answers: A, D
Explanation
To ensure secure remote access using SSH while blocking Telnet, you must configure the VTY lines appropriately. First, enter VTY line configuration mode using 'line vty 0 4'. Then, apply the 'transport input ssh' command to permit only SSH access. This configuration ensures that Telnet is blocked while allowing secure SSH connections.
- A. Correct.
The 'transport input ssh' command restricts access on the VTY lines to SSH only, which aligns with the requirement to block Telnet.
- B. Incorrect.
The 'transport input telnet' command allows only Telnet access, which does not meet the requirement to block Telnet access.
- C. Incorrect.
The 'transport input ssh telnet' command allows both SSH and Telnet access, which does not meet the requirement to block Telnet access.
- D. Correct.
The 'line vty 0 4' command is required to enter the VTY line configuration mode before applying access settings such as 'transport input ssh'.
- E. Incorrect.
The 'enable secret cisco123' command is used to set an encrypted enable password but is unrelated to the configuration of VTY line access.