Interview Questions.

Q1. On Which Port Dns Server Works ?

DNS servers use port fifty three with the aid of default. Incoming and outgoing packets have to be allowed onport 5@Also allow connections on port 921 in case you configure a light-weight resolver server.The DNS control software, rndc, connects to the DNS server with TCP port 953 by using default. Ifyou are jogging rndc at the call server, connections in this TCP port from localhostshould be allowed. If you are going for walks rndc on extra systems, allow connections toport 953 (or anything port you have selected to configure) from those additional systems.

Q2. What Are "mx Records"?

MX facts specify the mailing server of the area. An MX document shows to which computer a mail of a specific area ought to be sent. The MX file additionally consists of a priority wide variety, which can be used to decide numerous computers where the mail for the area can be sent. The first attempt is to supply the mail to the pc with the best priority (lowest value). If this strive fails, the mail goes to the next laptop (with a higher precedence cost), and so on.Check.Com IN SOA ......Mail test.Com IN SOA ......Mail IN A 192.1.1.2 IN HINFO AlphaServer UNIX IN TXT my server IN MX 30 mail2.Nextstep4it.Com IN MX 20 mail3.Nextstep4it.Com IN MX 10 mail2.Nextstep4it.Com

Q3. Explain "soa Record"?

The Start of Authority (SOA) record determines the name server this is an authoritative source of information for the precise area. There is usually simplest one SOA document in the file, and it's miles positioned at the beginning of the report of authoritative useful resource facts.

Q4. Tell Me five Types Of Dns Records?

A, NS, CNAME, SOA, PTR, MX.

Q5. What Are "hinfo And Txt Records"?

HINFO and TXT statistics are for data handiest. An HINFO document has  gadgets in its statistics component. The first item is facts approximately hardware, and the second one is records approximately software program. A TXT report incorporates a popular information string in its records element.Example :test.Com IN SOA ......Mail IN A 192.1.1.2IN HINFO My_Server UNIXIN TXT my server.

Q6. What Is Bind ?

BIND stands for Berkeley Internet Name Domain which is the maximum usually used Domain Name System (DNS) server on the Internet.

Q7. What Is Dynamic Dns?

Dynamic DNS a method of retaining a website call connected to a changing IP cope with as now not all computers use static IP addresses. Typically, while a person connects to the Internet, the person's ISP assigns an unused IP cope with from a pool of IP addresses, and this cope with is used most effective at some point of that particular connection. This approach of dynamically assigning addresses extends the usable pool of available IP addresses. A dynamic DNS provider provider uses a unique application that runs on the person's pc, contacting the DNS carrier whenever the IP cope with furnished by the ISP modifications and ultimately updating the DNS database to reflect the exchange in IP cope with.

Q8. What Is Root Name Server?

Root call server is an authoritative call server for the basis domain (for the dot). Each root call server is a primary server, which differentiates it from other call servers.

Q9. What Is "a Record"?

A (Address) records assign IP addresses to domain names of computers. The IP deal with cannot have a dot at the quit.

Q10. Explain "cname Record"?

Synonyms to domain names can be created the use of CNAME information. This is regularly called 'creating aliases for pc names'.

Q11. What Is The Role Of "named-checkzone Utility"?

The named-checkzone software checks the syntax and consistency of the sector document.

Syntax: named-checkzone [-dgv] [-c class] zone [filename]

Q12. Explain "ttl"?

Time to live. A 32-bit number indicating the time the particular RR may be stored legitimate in a server cache. When this time expires, the document must be considered invalid. The cost zero keeps nonauthoritative servers from saving the RR to their cache reminiscence.

Q13. What Is Stealth Name Server?

Stealth name server is a secret server. This kind of call server isn't published everywhere. It is handiest known to the servers that have its IP cope with statically indexed in their configuration. It is an authoritative server. It acquires the statistics for the quarter with the assist of a zone trfer. It can be the primary server for the sector. Stealth servers can be used as a neighborhood backup if the local servers are unavailable.

Q14. Explain "ptr Records"?

A Pointer Record (PTR) is used to trlate an IP deal with into a website name.

Q15. Which Are The Important Configuration Files For Dns Server ?

BIND makes use of /and many others/named.Conf as its most important configuration report, the /and so on/rndc.Conf file as the configuration document for call server manage utility rndc, and the /var/named/ directory for region documents and so on.

Q16. What Do You Mean By "resource Records"?

Information on domains and their IP addresses, as well as all the other statistics dispensed thru DNS is saved inside the reminiscence of name servers as Resource Records (RR).

Q17. What Is Secondary Name Server/slave Name Server?

Secondary name server/slave name server acquires facts approximately the area with the aid of copying the data from the primary name server (respectively from the grasp server) at regular time intervals. It makes no sense to edit those databases at the secondary name servers, even though they're stored at the nearby server disk due to the fact they may be rewritten in the course of in addition copying.

Q18. On Which Version Of Bind U Have Worked ?

BIND9

Q19. What Is Round Robin Dns?

Round robin DNS is typically used for balancing the load of geographically distributed Web servers. For instance, a corporation has one domain call and 3 same home pages residing on 3 servers with 3 exclusive IP addresses. When one person accesses the house page it is going to be sent to the primary IP cope with. The 2nd person who accesses the house web page can be despatched to the next IP deal with, and the 1/3 consumer can be despatched to the third IP deal with. In every case, as soon as the IP deal with is given out, it goes to the end of the listing. The fourth person, therefore, may be despatched to the primary IP address, and so forth.

Q20. What Is The Role Of Dns ?

A DNS server, or name server, is used to clear up an IP address to a hostname or vice versa.

Q21. What Is The Role Of "named-checkconf Utility"?

The named-checkconf utility exams the syntax of the named.Conf configuration file.

Syntax: named-checkconf [-t directory] [filename]

Q22. What Is Name Server?

A call server keeps information for the trlation of domain names to IP addresses and IP addresses to domains. The call server is a application that performs the trlation on the request of a resolver or every other call server.

Q23. What Is Primary Name Server Or Primary Master Server?

Primary name server/number one master is the primary records supply for the quarter. It is the authoritative server for the quarter. This server acquires records approximately its region from databases stored on a nearby disk. The number one server ought to be posted as an authoritative call server for the area in the SOA resource document, at the same time as the primary grasp server does now not want to be published.