Whole things come back.
This lesson we're going to talk about the basics of DNS server.
So what does DNS server DNS so Assad use to resolve and domain name includes IP address.
OK.
When you type any domain name into a browser.
So what happens is our browser contacts or local DNS server or find the IP address of the domain.
OK.
And if so we have that IP address in database.
Then it poured that IP address could and that said Get into our browser.
OK.
That Web site gets downloaded in Gohar browser OK.
This is how the procedure works.
So the job of DNS so you screw find the IP address for the corresponding domain.
So here let's understand this and with the help of an image demonstration.
OK before that I want to show you the basic structure of the Internet how it works.
OK.
At the top there on root servers.
OK at the top router was under these root servers there are top level domain names so us all get top
level domain and so this means it contains the database for block.
Com got made and or got us like comments and it is us who called us the source.
OK.
And so was there are second level domain names so as second level domain name so it means like Rupert
Murdoch.
It contains the database for such kind of second level domains.
And on the second Lumines there are some governments.
Ok not every Web site is having subdomain but some of the site content.
So that's why I'm showing here subdomains subelements means like community dot dot com.
OK.
When you go google to document the CT community you will find this common name in your browser and under
some Goman there are Web servers.
OK.
These are.
So we're actually with source on which our Web site is running.
OK you know listen we learn how to install our own web servers and how we open our own Web site with
the help of the web so what IP address.
OK.
So remembering the periscope Web site in the world is impossible for us as a human but remembering them
has a domain name is simple.
So that's why for such reason Goldman is so smart design.
OK.
They are designed to find the IP address for the domains.
OK.
So let's see here how the things work.
OK.
Suppose this client wanted to contact the proveably go over to dot com.
OK.
So what happens is when these Klan types in the browser then that is forwarded to local DNS so.
OK so the local DNS were searches a zone database or cache memory for the IP address of the débutante
dot com.
OK.
If it found the IP address then we'll get that site open in this machine if it contains the IP in its
local database or database.
And if the local DNS server does not Content-Type address then that is forwarded to the speedy and so
or Internet service providers the DNS server.
Ok then the ISP DNS server looks for the IP address of computer but got what got I'm in good luck or
good habits an IP address then forward that our machine and that side get awkward if it does not contain
that IP address then or what.
I use these DNS server for that.
Q. Re do the root servers globally there are 13 root servers are illegal in the world.
OK.
So first all agree is get transferred to one OBD-II.
Or we're kind of good that the roots are worth a look for the world.
We don't want to go cold.
OK.
So root server does not contain the actual IP address for it but it contains a database of dot com.
So in response were Since type resource dot com sources.
That is the top level government in service.
So the ISP is DNS so we're again seen in that jury to.
This was our top level domain name so US and the top level domain name so was looks for the breed of
dog with dot com and they said that we don't have the IP address of that which contains the database
info you to dot com.
So in response we send the IP address of securelevel domain names so us.
And now the ISP is DNS so are contacts.
The second domain names so was the soft of you the blue dot dot com and the Second Level Domain Name
Service says you don't how the IP address offered but which contains the information about subdomains.
OK.
So they sold their info or IP address of this subdomains back to the ISP DNS server.
Ok then the ISP DNS server contacts Deitz subelements.
OK.
And the subdomains contains the actual IP addresses of these verbs so as.
So in response they send the IP address of the Costella domains.
That is not open to come back dice Beazeley and is sold and then Hesperus use that IP address they send
back to our local DNS server and our local DNS so would record that into our local database.
And then this client computer establishes a direct connection with the web server with the help of that
IP address.
OK this is how the prosecutor goes at the background when we type any domain or browser OK this is a
long procedure that goes in the background.
But then in the next time when you're trying to open one to dot com then this procedure is let's skip
that because our local database contains this IP address.
So in this vein this procedure works OK.
Now understanding this I want to show you the typesof DNS servers.
OK.
So then our primary DNS so secondary DNS service.
OK so let's talk about this are you discuss Socola is master DNS server and it reads data from the locals
on file transfer it to the client.
OK so transferring data to the secondary DNS so is OK.
And the next type is secondary.
So it is also called how DNS server.
OK.
And its job is to receive the data from primary DNS service.
It receives the data automatically.
OK.
You can call it as a backup of the primary DNS server.
It contains the data every data that primary server is having.
OK.
So understanding the types I want to show you different records.
OK.
There are different records that does DNS server can hold.
The first one is Eric or it stands for I guess.
This record is used to going to an actual IP address of the server that is IP for IP address.
OK.
The next one needs a a he either got this record is as I recall.
And it does use hold the IP IP address or you can also call it and it maps the hostname puts 128 bit
IP address.
OK the next one is a MX record.
It's called as mailbox a car and it is used to point to your mail server.
OK.
And the next one is Butyric or this record is Coras point correct call it maps and IPV for ideas who
can only call name.
It can be used in reverse look up clinical limits an alternative name.
OK.
For the existing server and the next one is this record.
This record is called as names were record it is used to point to names so was for the domain.
The next one is saw a red card.
It is so called a stock of red card.
It contains some important information about the zone like a serial number.
It's a refresh rate expiry date forward zone.
OK.
We're going to learn everything practically.
How do these recalls what a DNS server.
So for now just understand.
What does it cost and what is the use of it.
The next one is sorry record we stand for services so it can be used to define DCP so on which the government
operates.
And the last one is the exterior is next reg or you can add information about the domain.
OK so this record can be used for that purpose.
OK.
In this way all these records are there all these records that are indeed OK.
Our number is called as Zone.
OK so all each Goman contains different zones.
OK.
You can arrange these recalls in a zone.
So we're going to learn in the next lesson about what this zone is how to create your own DNS so we're
OK we're going to learn everything practically.
But for now just understand these recalls and their use.
So the next lesson we're going to learn practically how Stalin configured you are only in this or.