Cisco Certified Network Associate (CCNA) Practice Exam

What is the main weakness of using Preshared Keys for IKE remote peer authentication?

1. It is not scalable

2. It is highly secure

3. It requires complex key management

4. It is difficult to implement

The correct answer is: It is not scalable

The main weakness of using Preshared Keys for IKE remote peer authentication is its lack of scalability. Preshared Keys work well in small networks, where the number of devices is limited, and the keys can be distributed manually. However, as networks grow in size and complexity, managing these keys becomes cumbersome. Each device that needs to communicate securely requires a copy of the preshared key, and any time there is a need to change the key for security reasons, the key must be updated on all devices manually. This process can become error-prone and inefficient in larger environments, making it challenging to maintain consistent security across all devices and leading to potential vulnerabilities if keys are not properly managed or updated. In larger network setups or more dynamic environments, automated key management solutions like public-key infrastructure (PKI) or dynamic key exchange protocols are more suitable as they can handle the increased complexity and scalability requirements more effectively.