300-445 Question 123
Select 4An enterprise network is experiencing intermittent connectivity issues across multiple branch offices. Upon investigation, the network team suspects that the issue is related to DNS resolution failures. The team identifies that the DNS configuration for some branch routers is not set correctly. Which of the following steps should be taken to resolve the DNS-related issues and ensure proper network assurance?
- A
Verify that all branch routers are configured with the correct DNS servers.
- B
Ensure that the DNS servers being used are reachable from the branch offices.
- C
Configure the routers to use only public DNS servers such as Google DNS (8.8.8.8) or Cloudflare DNS (1.1.1.1).
- D
Monitor DNS query response times to identify latency or failure patterns.
- E
Implement DNS caching on branch routers to reduce query times and improve performance.
Show answer and explanation
Correct answers: A, B, D, E
Explanation
DNS resolution is a critical component of enterprise network assurance. Ensuring that DNS servers are correctly configured and reachable is the first step in resolving DNS-related issues. Additionally, monitoring DNS performance and implementing caching can help improve reliability and performance. However, switching to public DNS servers without evaluating enterprise requirements is not always appropriate, as it may lead to security or operational challenges.
- A. Correct.
This option is correct. Incorrect DNS server configuration can lead to resolution failures, so verifying the DNS server settings is a critical step.
- B. Correct.
This option is correct. If the DNS servers are not reachable, DNS queries will fail, causing intermittent connectivity issues.
- C. Incorrect.
This option is incorrect. While public DNS servers can be reliable, enterprises often use internal DNS servers for custom configurations, security, and faster resolution. Switching to public DNS servers without evaluating the enterprise's needs may not resolve the issue.
- D. Correct.
This option is correct. Monitoring DNS query response times can help identify patterns of latency or failures, which are essential for troubleshooting and ensuring network assurance.
- E. Correct.
This option is correct. DNS caching can reduce the load on DNS servers and improve query response times for frequently accessed resources.