What is the main function of the TACACS+ protocol?

The primary function of the TACACS+ protocol is to manage access control and provide user authentication. TACACS+ stands for Terminal Access Controller Access-Control System Plus, and it is widely used in network environments to authenticate users trying to gain access to a network device or service.

When a user attempts to connect to a network device, TACACS+ communicates with a centralized authentication server to verify the user's identity and determine if they are permitted to access the requested resources. This helps maintain security by ensuring that only authorized users can access sensitive network devices and systems. Additionally, TACACS+ can offer detailed control over user permissions and can facilitate accounting for user activities, making it a powerful tool for managing access in complex environments.

Although the other options refer to important aspects of network security, they do not encompass the primary functions of TACACS+. For example, while encrypting data traffic is significant for securing communications, TACACS+ primarily focuses on authentication rather than direct data encryption. Similarly, monitoring user activities is an important security practice, but it is not the core function of TACACS+. Establishing VPN connections securely is another vital aspect of network security but is not associated with the TACACS+ protocol directly.