DNS Server Interview Questions and Answers

Find below Interview questions and answers related to windows 2008 DNS server, highly recommended questions for MCSE, MCSA, and Network engineers. These questions will help you for job interviews and provide practical knowledge as well.

Top Questions and Answers for DNS Server Interview:

1. What are the best tools used to troubleshoot DNS servers?

NSlookup and DNSCMD

(netshell for WINS server)

2. What is the use of Netbeui Protocol?

The protocol is mainly used with windows 95/98 operating systems which are configured in workgroups in small offices.

3. What Is Subnet Masking?

Separating the host portion of an IP address from the network ID

4. What is Classful Addressing?

When the networks are divided in octal level the address derived are known as classful addressing. For computers on the same network segment need to have same network ID, systems in different logical network cannot communicate without router.

5. What is a router?

A router is to send IP Packets to remote network either directly or by sending to another router.

6. Why do we need a default gateway configured in DNS?

To send IP Packets from one network to another network segment we need to configure a default gateway.

7. What’s the difference between DNS and WINS servers?

DNS: the servers resolve the hostname to IP address

WINS: the servers resolve NetBIOS names to IP address

8. What is Host File?

The file that is stored locally on every computer that maps IP address to host names.

9. What is a Lmhosts file?

The file that is stored locally on every computer which maps IP address to NETBIOS names.

10. What is Resolver Cache?

The resolver cache is where a computer stores its previously queried FQDN to IP address mapping.

  • To see the content of the resolver cache from command prompt, type: ipconfig /display DNS
  • To clear the content of the local resolver, type: ipconfig /flushdns

11. What is the Command used to view the Netbios Cache on a system?

Nbstat –c

12. What are Dynamic Updates?

Refers to a system’s ability to automatically register its IP address and host name with its primary DNS server.

13. What are Forwarders?

When a DNS server doesn’t know the answer of a particular name resolution, the query is sent to forwarder.

14. What is Caching Only server?

A caching only server refers to a DNS server with no configuration zones, it resolves host name to ip address and stores the mapping information in its cache. If a client requests a host name, the DNS server provides the mapping information in its cache.

15. What are Resource Records?

Names and addresses in the DNS zones are referred to as resource records.

16. What is the use of Round Robin?

It provides static load balancing.

You enter multiple A records for the same host each with different IP address. Then enable round robin with multiple A records in the zone. Each time a client asks the DNS server for the IP address, it provides a different answer.

17. What is Netmask Ordering?

If multiple A records exist for the same host and list IP address on different subnet.

18. What is the use of Clear Cache?

It allows you to remove all cached resource records in a DNS server’s cache.

Command: dnscms dell.com /clearcache

19. What command is used to check and verify DNS records for a particular domain?


20. What is the best tool to troubleshoot Name Resolution Problems?


Command: nslookup domain name

21. What is the use of LS Command in DNS Server?

It is used to display the content of a particular zone on the server. If the zone is not configured for a zone transfer, then you will receive a refused error.

Ls –a dell.com –returns the alias name (CNAME in a domain)

Ls –d dell.com –returns all records in the specified domain

22. What is delegation of authority?

It refers to delegating name space to another domain. It’s giving control of the DNS domain to another domain. When the delegation is done, the storage database is split.