In this lecture, we'll see the many steps of named resolution.
So in this lecture, we will learn about name resolution process and how Deana's converts names to IP
addresses and vice versa.
What is name resolution?
Name resolution is a matter of converting an IP address to a user friendly computer name.
For example, if you want to connect to Microsoft dot com, you enter Microsoft dot com in the United
and not the IP address.
The process that goes behind directing the Microsoft dot com to its IP address is known as name resolution.
Hostname resolution is defined as translating a hostname to an IP address.
The entire hostname can be no longer than 255 characters and must be alphanumeric, including hyphens
and periods.
But periods can only be used between labels and at the end of a fully qualified domain name.
That is f the end.
What is fqdn?
F Q. The N is a name we have seen so far as fully qualified domain names, they are sometimes written
more formally the training period, for example, Amitay Dot Edu Dot.
This training period indicates that the name is complete.
No additional information should be added to the name when the performing Unnim resolution.
And opposite to this, it is unqualified on unqualified domain name, which is used in combination,
the default to mean a domain search list set the system configuration.
What is DNS space?
The DNS namespace is the set of all names used with d'Eon.
As this space is partitioned hierarchically and in case sensitive.
The current DNS namespace is a three of domains with an unnamed route at the top.
The top echelons of the tree are the so-called top level domains.
That is the LDA, which include generic top level domains, country code, top level domains, internationalized
country code, top level domains and a special infrastructure top level domain called for historical
reasons, ARTPOP.
So let us now see how aname resolution process occurs in the image.
You can see that.
Let us say suppose you type w w w dot abc dot com in your browser.
Now your browser doesn't know what ABC dot com means because a browser redirects only when it has been
directed to an IP address.
So browser passes that request to resolve your resolver is nothing but an Internet service provider.
Internet service provider has the ISP table and its cache.
So the ISP table cache is a table which consists of the website name alongside its IP address.
Let us consider the case with the resolver does not find IP address for w w w dot a C dot com.
So the resolver passes the query to the DNS local server.
Now the DNS local server passes the query to the router DNS server.
In our case the root server is dot com.
So the root server replies that, OK, this is a dot com and please check in the DNS dot com top level
domains.
So the DNS root server replies back to the DNS local server saying that please check the domain in dot
com top level domain list.
DNS logos is OK and DNS Local again puts a query to DNS dot com top level domain.
Now DNS dot dot com top level domain gives an answer and says, okay, this is A.B.C., so please check
in the ABC dot com namespace.
So DNS Local again puts a query to domain name servers, ABC dot com space and finally ABC dot com replies
with the IP address and now DNS Local also update the IP address in its own table and forwards that
IP address to the resolver resolver to put that IP address into its stable and finally it.
And so that IP address to your browser.
Now all this process happens in a fraction of seconds and this process is known as the name resolution
process.
Let us have a quick recap, so we saw what is named resolution, we saw what our top level domains,
what are authority domains and what are lower level domains.
We also saw about the named resolution process and the dayanim namespace.
In the next lecture, we will see which protocols do we use for establishing connection with the name
server.
Now, you must have got the question, why do we need.
Why do we need to use a protocol?
OK, so this answer will be answered in the next lecture.