100-160 Question 61
Select 3A user reports that they are unable to access a specific website, but other websites load without issue. As a cybersecurity technician, you suspect the problem may be related to DNS. Which of the following protocols or tools would you use to troubleshoot and verify if the DNS is functioning correctly?
- A
Ping the website's domain name to check for a response
- B
Use the nslookup command to query the DNS server
- C
Send an ARP request to the website's IP address
- D
Check the DHCP logs for the user's assigned IP address
- E
Use the traceroute command to identify the network path
Show answer and explanation
Correct answers: A, B, E
Explanation
When troubleshooting DNS issues, tools like Ping and nslookup are essential for verifying domain name resolution and DNS server responses. Traceroute can complement this by showing the end-to-end path and ensuring DNS resolution before the trace begins. ARP and DHCP are unrelated to DNS functionality and are not relevant for this specific scenario.
- A. Correct.
Ping can confirm whether the domain name resolves to an IP address and if the server responds, making it a useful first step in DNS troubleshooting.
- B. Correct.
The nslookup command allows you to directly query DNS servers and verify if the domain name is resolving correctly, which is crucial for diagnosing DNS issues.
- C. Incorrect.
ARP is used to resolve IP addresses to MAC addresses on a local network and is unrelated to DNS resolution or website access.
- D. Incorrect.
DHCP is responsible for assigning IP addresses to devices, but it is not directly involved in DNS resolution for websites.
- E. Correct.
Traceroute can help identify if there are any network path issues, and it verifies if the domain name resolves to an IP before starting the path trace.