CCNA Network Services and Security Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  FTP

  Why it's wrong here

  FTP (File Transfer Protocol) is a file-transfer service that uses TCP port 21 for control and a separate dynamic data port, transmitting usernames, passwords, and file contents in cleartext by default. Although it requires authentication, its purpose is moving files between hosts, not offering a command-line shell for device configuration. The lack of encryption makes it vulnerable to packet sniffing, and its interactive commands are limited to file operations, not device management commands.

  When this WOULD be correct

  If the exam question asked for a protocol used for file transfer that supports encryption, such as FTPS or SFTP, then FTP could be considered correct in that context. This would shift the focus from remote CLI management to secure file transfer.

• ✓

  SSH

  Why this is correct

  SSH (Secure Shell) provides an encrypted, authenticated remote CLI session over TCP port 22, protecting both login credentials and subsequent commands from eavesdropping or session hijacking. It is the industry-standard replacement for Telnet because it ensures confidentiality and integrity of the management traffic on untrusted networks. Unlike the other options, SSH is purpose-built for secure interactive terminal access to network devices.

• ✗

  TFTP

  Why it's wrong here

  TFTP (Trivial File Transfer Protocol) is a lightweight, lockstep file-transfer protocol that runs over UDP port 69 with no authentication, encryption, or even directory listing capability. It is designed solely for simple read/write operations, such as pushing configuration files or IOS images to a device, not for interactive remote CLI sessions. Because it lacks any session concept, it cannot provide a login-oriented command interface for administration.

  When this WOULD be correct

  If the exam question asked which protocol is used for transferring files in a simple manner without encryption, TFTP would be the correct answer. For example, a question could specify 'Which protocol allows for file transfers without security features?'

• ✗

  SNMPv1

  Why it's wrong here

  SNMPv1 is a network management protocol that uses community strings as plaintext passwords and typically operates over UDP port 161 for monitoring and UDP 162 for traps, allowing GET/SET operations on managed objects via MIBs. It does not provide a CLI interface at all; instead, it is used by NMS applications to poll or configure device parameters programmatically. Moreover, SNMPv1 has no encryption or robust authentication, so it is insecure for remote administration and cannot replace Telnet for CLI access.

  When this WOULD be correct

  If the question asked for a protocol used for network management that does not require encryption, SNMPv1 would be the correct answer. For example, a question might specify the need for a simple, unencrypted protocol for monitoring network devices.

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.

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?”