Domain Name System Interview & Question

Question 8. What Is Caching Only Server?

Answer :

Caching-only servers are those DNS servers that only perform name resolution queries, cache the answers, and return the results to the client. Once the query is stored in cache, next time the query in resolved locally from cached instead of going to the actual site.

Question 9. What Is Aging And Scavenging?

Answer :

DNS servers running Windows Server support aging and scavenging features. These features are provided as a mechanism to perform cleanup and removal of stale resource records from the server and zone. This feature removes the dynamically created records when they are stamped as stale.
By default, the aging and scavenging mechanism for the DNS Server service is disabled.
Scavenging and aging must be enabled both at the DNS server and on the zone

Question 11. What Is Forwarding In Dns?

Answer :

A forwarder is a feature in DNS server that is used to forward DNS queries for external DNS names to DNS servers outside of that network. We ca configure a DNS server as a forwarder to forward the name query to other DNS servers in the network when they cannot resolve locally to that DNS server.

Question 12. What Is Conditional Forwarding In Dns?

Answer :

We can configure the DNS server to forward queries according to specific domain names using conditional forwarders. In this case query is forward to an IP address against a DNS domain name.

Question 14. What Are Tools For Troubleshooting Of Dns?

Answer :

DNS Console, NSLOOKUP, DNSCMD, IPCONFIG, DNS Logs.

Question 15. How To Check Dns Health?

Answer :

Using the DCdiag.
i.e. (dcdiag /test:dns /v /e)

> Properties of a Zone ? 
General, SOA, NAMESERVER, WINS, Security, and ZONE Transfer.

> What is scavenging?
Finding and deleting unwanted records.

> What are SRV records? 
SRV are the service records, there are 6 service records. They are useful for locating the services.

What is WINS server? where we use WINS server? difference between DNS and WINS?
WINS is windows internet name service used to resolve the NetBIOS(computer name)name to IP address.This is proprietary for Windows.You can use in LAN.DNS is a Domain Naming System, which resolves Host names to IP addresses. It uses fully qualified domain names. DNS is an Internet standard used to resolve host names.

> Before installing your first domain controller in the network, you installed a DNS server and created a zone, naming it as you would name your AD domain. However, after the installation of the domain controller, you are unable to locate infrastructure SRV records anywhere in the zone. What is the most likely cause of this failure?
The zone you created was not configured to allow dynamic updates. The local interface on the DNS server was not configured to allow dynamic updates.

Question 22. What Is The Role Of Udrp?

Answer :

o    UDRP stands for Uniform Domain Name Dispute Resolution Policy that is being given by the Internet Corporation for Assigned Names and Numbers (ICANN).

o    UDRP provides the recommendations and uses the reports made by WIPO. This way the report is being analyzed and certain actions taken on that.

o    The Report in the WIPO on the Internet Domain Name Process provides the information of disputes and problems.

o    UDRP provides a way to report the problems or conflicts that can come between the trademarks and the domain names.

o    The reports produced can be identified by the use of First WIPO Process and it can be addressed more in other alternate port domain.

Question 23. Do You Know How Does Udrp Function?

Answer :

1. A trademark holder is involved in the whole process that provides a domain name registration and works under UDRP system.

2.      The standard disputes are recorded and clauses are being made with terms and conditions using the gTLD domain name registration.

3.      UDRP allows the complaints to be filed with a resolution service provider and specifies the domain name for which the question is being raised.

4.      The grounds on which the resolution is being provided include the domain name to be identical or similar to the names of trademarks.

5.      The respondent is being given the chance to defend the case by putting the views on the allegations and provides a team to assist the respondent on this matter.

Question 25. What Is The Purpose Of Domain Name Space?

Answer :

o    ICANN also known as Internet Corporation for Assigned Names and Numbers provide tools to manage the hierarchy.

o    The management of it includes the top level domains that are being developed or that are under process.

o    The architecture of it is designed using the Internet domain name space as it allows the authorization to be done from the registrars.

o    The Domain name space is required to allow the hosting of the files andeasy management through the portal.

o    It allows a hierarchical relationship to be maintained and organized in the zones that are being served by the domain name servers.

Question 32. What Are The Rules For Registration Of .biz, .com, .info, .name, .net And .org Names?

Answer :

o    The domain names can be registered without any restriction and provide open secure channel to file the names for registration.

o    The domain names that are shown differently used for different domains and industries that involves the internet infrastructure.

o    The activities for the registration being performed on the basis of domains that needs to be taken for example .org.

o    There are different domains with different purposes like .org is used for non-commercial organizations and .biz for business purposes.

o    After domain registration some legal forms need to be filled to register the domain with the registrar after checking the availability.

o    Question 33. What Is Authoritative Name Server?

o    Answer :

o    An authoritative name server is a name server that gives answers that have been configured by an original source, for example, the domain administrator or by dynamic DNS methods, in contrast to answers that were obtained via a regular DNS query to another name server. An authoritative-only name server only returns answers to queries about domain names that have been specifically configured by the administrator.

o    Question 41. What Is The Main Purpose Of Srv Records?

o    Answer :

o    SRV records are used in locating hosts that provide certain network services.

o    Question 45. What Is Wins Server? Where We Use Wins Server? Difference Between Dns And Wins?

o    Answer :

o    WINS is windows internet name service used to resolve the NetBIOS(computer name)name to IP address.This is proprietary for Windows.You can use in LAN.DNS is a Domain Naming System, which resolves Host names to IP addresses. It uses fully qualified domain names. DNS is an Internet standard used to resolve host names

o    Question 44. Soa Records Must Be Included In Every Zone. What Are They Used For?

o    Answer :

o    SOA records contain a TTL value, used by default in all resource records in the zone. SOA records contain the e-mail address of the person who is responsible for maintaining the zone. SOA records contain the current serial number of the zone, which is used in zone transfers.
By default, if the name is not found in the cache or local hosts file, what is the first step the client takes to resolve the FQDN name into an IP address? Performs a recursive search through the primary DNS server based on the network interface configuration.

1.      Question 48. How To Enable Dynamic Updates In Dns?

Answer :

Start>Program>Admin tools> DNS >Zone properties.

2.      Question 49. What Are The Properties Of Dns Server?

Answer :

INTERFACES, FORWARDERS, ADVANCED, ROUTINGS, SECURITY, MONITORING, LOGGING, DEBUG LOGGING.

Question 53. What Are The Types Of Srv Records?

Answer :

MSDCS:Contains DCs information.

TCP:Contains Global Catalog, Kerberos & LDAP information.

UDP:Contains Sites information.

Sites:Contains Sites information.

Domain DNS Zone:Conations domain?s DNS specific information.

Forest DNS zone:Contains Forest?s Specific Information.

Question 55. What Is Primary, Secondary, Stub Zone?

Answer :

Primary Zone: - zone which is saved as normal text file with filename (.dns) in DBS folder. Maintains a read, write copy of zone database.
Secondary Zone: - maintains a read only copy of zone database on another DNS server. Provides fault tolerance and load balancing by acting as backup server to primary server.
Stub zone: - contains a copy of name server and SOA records used for reducing the DNS search orders. Provides fault tolerance and load balancing.

Question 59. By Default, If The Name Is Not Found In The Cache Or Local Hosts File, What Is The First Step The Client Takes To Resolve The Fqdn Name Into An Ip Address?

Answer :

Performs a recursive search through the primary DNS server based on the network interface configuration.