Network Defense Essentials (NDE) 2025 – 400 Free Practice Questions to Pass the Exam

The correct choice is SSH (Secure Shell) because it is specifically designed to provide secure communication over an unsecured network. SSH encrypts the data transmitted between the client and server, which protects it from being intercepted by unauthorized parties during transmission. This encryption makes it significantly more difficult for attackers to carry out sniffing attacks, where they would attempt to capture sensitive data being communicated over the network.

In contrast, the other protocols listed do not primarily focus on securing terminal or command-line communications against sniffing. While RADIUS (Remote Authentication Dial-In User Service) and TACACS+ (Terminal Access Controller Access-Control System Plus) are protocols for authentication, authorization, and accounting, they do not inherently encrypt all the data in the way SSH does. PPTP (Point-to-Point Tunneling Protocol) provides a method for implementing virtual private networks, but it is considered less secure compared to SSH due to its vulnerabilities and weaker encryption standards. Therefore, SSH is the most appropriate choice for securing communications against sniffing attacks.