DNS = Domain Name System

 

DNS

 

1.Why we use DNS?

è Its’s Use for Name and Resolution

            IP toè convert name / Name toè convert IP

           

            Now, if we search in IP address (172.217.194.138)

           

 

2.  Is it used to eliminate broadcasting into local Domain?

            è  yes

 

3. Give difference between Iterative and Recursive Query?

Recursive  : A recursive DNS lookup is where one DNS server communicates with several other DNS servers to hunt down an IP address and return it to the client. This is why we call them recursive.

Iterative : This is in contrast to an iterative DNS query, where the client communicates directly with each DNS server involved in the lookup.

4. How many root server are available in the world?

è 13.

5. Write some name of TLD (Top Level Domain) ?

            è org, com, net etc.

6. What is the command to find DNS cache in your local machine?

            è ipconfig /displayDNS

           

 

7. Give the location of your host file of your machine?

è C:\Windows\System32\drivers\etc

 

8. What does IP Scanner?

è We can find networking IP which are up, we also know the machine name and mac address.

 

 

9. How DNS work?

 

 

 

 

Ø Step 1 – Send a Request to Resolve a Domain Name

•  Step-2  - Search for an Ip Locally

 

Ø Step 3 – Contact ISP and its Recursive DNS Server to Resolve a Domain                         Name

 

 

 

Ø Step 4 – Ask Outside DNS Servers to Provide an IP Address

 

·        Root domain nameservers.

 

·        TLD nameservers

·        Authoritative nameserver

Ø Step 5 – Receive the IP Address

To learn more click on this è How Does DNS Work ?