Question 28

nslookup is the appropriate command for testing DNS resolution.

The technician should use the nslookup command to perform a simple query that verifies DNS resolution functionality. This command allows the user to query DNS servers directly to check the resolution of domain names to IP addresses.

A) nslookup

This option is correct as nslookup is specifically designed for querying DNS records. It provides a straightforward way to check if a domain name resolves to the correct IP address, making it the ideal tool for diagnosing DNS issues.

B) ping

While ping can be used to test connectivity to an IP address or hostname, it does not directly verify DNS resolution. If the DNS is not functioning but the IP address is known, ping may still succeed, which does not help in diagnosing DNS issues specifically.

C) tracert

Tracert is used to determine the path that packets take to reach a destination, but it does not perform DNS queries. It can show where packets are being dropped in the network but does not help in resolving domain names to IP addresses.

D) arp

The arp command is used to display and manipulate the ARP (Address Resolution Protocol) cache, which maps IP addresses to MAC addresses. It does not perform any DNS resolution tasks and is therefore not suitable for the technician's needs.

Conclusion

In summary, nslookup is the only command among the choices that is specifically tailored for testing DNS resolution. The other options, while useful in their own right, do not address the need for verifying domain name resolution, making nslookup the definitive correct choice for this scenario.