Which of the following network security protocols protects from sniffing attacks by encrypting entire communication...

TACACS+ (Terminal Access Controller Access-Control System Plus) is a network security protocol that provides centralized authentication for users who are attempting to gain access to the network. It is designed to protect against sniffing attacks by encrypting the entire packet, which includes both the authentication credentials and the subsequent communication after the credentials have been accepted. This encryption ensures that sensitive information such as user passwords is not transmitted in plain text where it could be intercepted by unauthorized individuals. Unlike RADIUS, which only encrypts the password, TACACS+ encrypts the entire authentication process, providing a higher level of security.

References: The information provided here is based on my training data up to September 2021, which includes knowledge of network security protocols and their functionalities. For the most current and detailed explanations, please refer to the latest Network Defender (CND) documents and study guides from the EC-Council and other authoritative sources on network security.