Cisco Exam 100-490 Topic 3 Question 51 Discussion

* A. SSH...secure remote access: This is correct. SSH (Secure Shell) is designed specifically for secure remote access. It utilizes strong encryption to protect data transmissions, including login credentials and commands.

* B. Telnet...secure remote access: This is incorrect. Telnet is inherently insecure as it transmits all data, including sensitive passwords, in cleartext.

* C. SSH uses...TCP port 23: This is incorrect. SSH uses TCP port 22 by default, while Telnet uses TCP port 23.

* D. Telnet preferred...security reasons: This is incorrect. SSH is vastly preferred over Telnet due to its strong security features.

* E. Telnet connection...router reboots: This is correct. Telnet connections are not persistent, so a router reboot disrupts them. This re-enforces their lack of suitability for critical management tasks.

Key Points:

* Security: SSH is the recommended protocol for remote access to network devices due to its strong encryption and authentication mechanisms.

* Persistence: Telnet connections are temporary and get disrupted on events like router reboots.