300-445 Question 127
Select 3A global enterprise is experiencing intermittent failures when resolving domain names for critical application servers hosted in a hybrid cloud environment. The network team suspects that the issue lies with DNS configuration. After an investigation, they find that the DNS servers are configured with incorrect forwarders, leading to delays and occasional failures. What steps should the team take to resolve the issue and improve DNS reliability?
- A
Update the forwarders on the DNS servers to point to public DNS services such as Google DNS or Cloudflare DNS.
- B
Implement DNS caching on the local DNS servers to reduce query latency for frequently accessed domains.
- C
Configure a secondary DNS server to provide redundancy in case of failure of the primary server.
- D
Enable DNSSEC validation to ensure that domain resolutions are secure and prevent spoofing.
- E
Increase the TTL (Time-To-Live) value for DNS records to reduce the frequency of queries to the forwarders.
Show answer and explanation
Correct answers: A, B, C
Explanation
To resolve intermittent DNS failures and improve reliability, the team should focus on correcting misconfigurations and enhancing DNS infrastructure. Updating forwarders to point to reliable public DNS services ensures accurate and responsive query resolution. Implementing DNS caching reduces latency for frequently queried domains, and adding a secondary DNS server provides redundancy to prevent outages. While DNSSEC and TTL adjustments have their benefits, they do not address the specific problem of incorrect forwarders or query reliability.
- A. Correct.
Correct. Updating the forwarders ensures that DNS queries are directed to reliable and responsive external DNS servers, mitigating delays and failures.
- B. Correct.
Correct. DNS caching can significantly reduce query latency, improving the performance and reliability of DNS resolutions for frequently accessed domains.
- C. Correct.
Correct. Configuring a secondary DNS server adds redundancy, ensuring DNS resolution continues to function even if the primary server fails.
- D. Incorrect.
Incorrect. While enabling DNSSEC improves security, it does not directly address the issue of intermittent failures caused by incorrect forwarders.
- E. Incorrect.
Incorrect. Increasing the TTL value can reduce query frequency but does not resolve the root cause of the intermittent failures.