CompTIA CASP+ Practice Test

Which factor is crucial when configuring secure zone transfers in DNS?

1. Implementing HMAC authentication

2. Disabling zone transfers entirely

3. Using plain text for configuration

4. Configuring dynamic DNS updates

The correct answer is: Implementing HMAC authentication

Implementing HMAC authentication is crucial when configuring secure zone transfers in DNS because it ensures the integrity and authenticity of the data being exchanged between DNS servers. HMAC, or Hashed Message Authentication Code, utilizes a shared secret key along with a cryptographic hash function to create a unique signature for each message. This signature is used to verify that the data has not been altered during transit and that it comes from a legitimate source. Zone transfers can expose a significant amount of information about a domain's structure and resource records, making it essential to protect this data from unauthorized access or tampering. By using HMAC authentication, administrators can restrict access to zone transfer requests, ensuring that only authorized servers are allowed to receive this sensitive information. This significantly strengthens the overall security of the DNS infrastructure. Disabling zone transfers entirely can reduce the risk of data exposure, but it also limits the ability for secondary DNS servers to receive updates, impacting redundancy and load balancing. Using plain text for configuration would expose sensitive information during transmission, which is inherently insecure. Configuring dynamic DNS updates involves a different function related to real-time resource record changes and does not specifically address the security of zone transfers. Thus, the use of HMAC authentication is key in ensuring that zone transfers are performed