How a DNS Server (Domain Name System) works.

By | February 14, 2020


In the world of networking, computers
don’t go by names like humans do, they go by numbers, because that’s how computers
and other similar devices talk and identify with each other over a network,
which is by using numbers such as IP addresses. Humans on the other hand are
accustomed to using names instead of numbers, whether is talking directly to another
person or identifying a country, place, or thing, humans identify with
names instead of numbers. So in order to bridge the communication gap between
computers and humans and make the communication of a lot easier networking engineers developed DNS, and
DNS stands for a domain name system. And DNS resolves names to numbers, to be more
specific it resolves domain names to IP addresses.
So if you type in a web address in your web browser, DNS will resolve the name to
a number because the only thing computers know are numbers. So for
example if you wanted to go to a certain website you would open up your web
browser and type in the domain name of that website, so for example let’s use
yahoo.com. Now technically you really don’t have to type in yahoo.com to
retrieve the Yahoo web page, you can just type in the IP address instead if you
already knew what the IP address was, but since we are not accustomed to
memorizing and dealing with numbers, especially when there are millions of
websites on the internet, we can just type in the domain name instead and let
DNS convert it to an IP address for us. So back to our example, when you typing
yahoo.com your web browser the DNS server with search through its
database to find a matching IP address for that domain name, and when it finds
it it will resolve that domain name to the IP address of the Yahoo web site, and
once that is done then your computer is able to communicate with a Yahoo web
server and retrieve the webpage. So DNS basically works like a phone book, when
you want to find a number, you don’t look up the number first, you look up the name
first then it will give you the number. So to break this down into further
detail let’s examine the steps that DNS takes. So when you type in yahoo.com in
your web browser and if your web browser or operating system can’t find the IP
address in its own cache memory, it will send the query to the next level to what
is called the resolver server to resolver server is basically your ISP or
Internet service provider, so when the resolver receives the query, it will check
its own cache memory to find an IP address for yahoo.com, and if it can’t
find it it will send the query to the next level which is the root server. The root servers are the top or the root
of a DNS hierarchy. There are 13 sets of these root servers and they are
strategically placed around the world, and they are operated by 12 different
organizations and each set of these root servers has their own unique IP address.
So when the root server receives the query for the IP address for yahoo.com,
the root server is not going to know what the IP address is, but the root
server does know where to send the resolver to help it find the IP address.
So the root server will direct the resolver to the TLD or top-level domain
server for the dot-com domain. So the resolver will now ask the TLD server for the
IP address for yahoo.com. The top level domain server stores the
address information for a top-level domains, such as.com and.net dot org and
so on. This particular TLD server manages the dot-com domain which yahoo.com is a
part of. So when a TLD server receives the query
for the IP address for yahoo.com, the TLD server is not going to know
what the IP addresses for yahoo.com. So the TLD will direct the resolver to the
next and final level, which are the authoritative name servers. So once again the resolver will now ask
the authoritative name server for the IP address for yahoo.com. The authoritative name server or servers
are responsible for knowing everything about the domain which includes the IP
address. They are the final authority. So when the authoritative name server
receives the query from the resolver, the name server will respond with the IP
address for yahoo.com. And finally the resolver will tell your computer the IP
address for yahoo.com and then your computer can now retrieve the Yahoo web
page. It’s important to note that once the
resolver receives the IP address, it will store it in its cache memory in case it
receives another query for yahoo.com so it doesn’t have to go through all those
steps again.

100 thoughts on “How a DNS Server (Domain Name System) works.

  1. PowerCert Animated Videos Post author

    Wifi router that I recommend (affiliate) https://amzn.to/2Jv577C

    Reply
  2. Unlimited Media PC Systems Post author

    Ok Guys… You make great job 🙂 I'm proud as IT spec, that You make for people great info 🙂

    Keep on, You have my sub 🙂

    Reply
  3. Sameet Sable Post author

    wow…..i took 5 lectures still couldnt understand…u explained it in a few mins

    Reply
  4. Eveline Garcia Post author

    I been looking for an explanation like this, you really made my job so much easier!!! Thanks a looot

    Reply
  5. MrVatnik Post author

    Охххх нам бы эти видео 10 лет назад!!!! =)))

    Reply
  6. Blanca NBX Post author

    I love these videos. I am a new IT student taking an online class. I am very thankful for these videos.

    Reply
  7. mat joe Post author

    Thank you power cert, I am have been following you for a long time and your videos are a very clear and perfect explanation, but there is more dislike that like, I don't understand, you are doing great.

    Reply
  8. Zealot Patriot Post author

    Why did the Root Server and the TLD Server not know the IP address? Is this always the case or only in this example?

    Reply
  9. Social Network Snapigram Post author

    5 star education and more then 5 Stars animation fantastic

    Reply
  10. Zealot Patriot Post author

    Does the (dot)com domain consist of all of the Authoritative Name Servers around the world, that store web addresses ending in (dot)com, and do the TLD Servers have all of the Authoritative Name Server addresses from around the world? Thank you for you help, you are excellent!

    Reply
  11. Nasreen Khan Post author

    Tnx gentlemen you have provide us a comprehensive awareness & knowledge about DNS💖💖💖💖💖

    Reply
  12. Daniel Astillero Post author

    Who owns the Root Name Servers? Where are these servers located? How do they make money?

    Who owns the TLD servers? Where are these servers located? can imagine how they earn money because getting a .com requires one to pay for it. GoDaddy offers a .com does that mean that it is a TLD? If so, does it mean that being a TLD is like franchising a McDonald's branch?

    What happens when I found the root name servers and make them all explode? Does it mean that DNS-ing is over?

    Reply
  13. Slightly Rude Post author

    Very good video. Simple to understand for a network newbie like myself. Thank you!

    Reply
  14. chessthisout Post author

    So in other words it's like calling mum, how to sole some strange problem. I don't know but ask dad, he might know, however he is abroad now. I give you his phone number. You call. Hey dad how to sole this problem? I don't know but I know a world class expert in this matter who will help you, here is his phone number. You call and explain your problem again. He says, well I don't know but I know Mr. Matrix from another dimension who knows everything, here is his phone number. You call Mr. Matrix and he gives you the answer. Ha!

    Reply
  15. Santhosh Sundar Post author

    wow! I LOVE THE VIDEO MAKING., its very easy to learn the process, im going to follow your channel.

    Reply
  16. Colin Berrell Post author

    Great simple delivery, outstanding displays and graphic, thank you so much

    Reply
  17. Jordan McDuff Official Post author

    Video: "let's use…"
    Me: Google dot com
    Video: YAHOO DOT COM
    Me: *sigh*

    Reply
  18. Hamouda Rawdh Post author

    i have a question ! why doesn't the resolver go directly to the authoritative name server ???? why would it go around this whole tour ??? thanks in advance =D

    Reply
  19. jack171380 Post author

    What I learned: 75% of servers on the internet dont know where yahoo.com is

    Reply
  20. Favour Shomoye Post author

    This channel literally stopped me from flunking computing
    Like if u can relate
    l
    Thank You So much!!

    Reply
  21. Power Glove Post author

    So why do we need a root server or a TLD if it just goes to the name server anyway?

    Reply
  22. Thinker Entermen Post author

    I got some doubts please help me with this.
    1) why don't Resovler sever (ISP) go directly to ANDS. If both route server and TLD don't have IP.

    Reply
  23. DINESH RATHEE Post author

    I was wondering if you can add a practilce scenrio with DIG commands etc to explain people ( deiv deep ) like how to find Resolver in system , how to check details of Root Name server, TLD and Authorative NS ( like any example ) showing how it works 🙂

    Rest the definition was great !

    Reply
  24. Gururaj BN Post author

    You are a great teacher. Last few days, I have been watching your videos. As a lay person, I get to learn many things about comptuers, and internet protocol. Many thanks for your efforts. Please make a video about Clouds and Cloud-based services, and how information on cloud is located by the computers?

    Reply
  25. Marimba Nation Post author

    the god of explanations, I have not seen this amazing explanation ever

    Reply
  26. Aduco Ayasiin Post author

    RESOLVER : hey root what is the phone number of that beautiful girl?
    ROOT SERVER : I don't know 🤨.
    RESOLVER : hey TLD what is the phone number of that beautiful girl?
    TLD : I don't know 🤨.
    RESOLVER : hey NAME what is the phone number of that beautiful girl?
    NAME : The phone number is 143

    Reply
  27. Олександр Кухар Post author

    Hi! Thank you for your work, your videos are amazing!!!
    Basically you give a good explanation of DNS in this video, but some points are missed, I must admit. Let me try to explain what I mean:
    1. The reason of using DNS is not only the network address translation from human-readable form to computer understandable format. Firstly it allows to access different servers by one convenient name (you can transfer your site to new server with different IP address or just sale your domain name to someone else). Secondly it allows you to provide different services on the same domain name (for example, you may wish to have your own mail server on your domain).
    2. Some people in comments are confused about "server that knows everything", so it is important to make clear that such server knows everything about its domain zone.

    Thank you for your video!

    Reply
  28. Puppet Master Marketing Post author

    I've been working with DNS records for a while. I know what to do when I'm rerouting a domain or setting up email but I never understood how it worked. This video just blew my mind. So simply put. You guys/gals rock!

    Reply
  29. Tushar gera Post author

    A very good explanation. And I am a Network Engineer in Cisco and I am telling you from the experience. A very few people know this concept of TLD

    Reply
  30. Shubham Goswami Post author

    Thank you Sir for the amazing video and explanation is really very simple, I have a silly question if you can please answer, If Root server and TLD doesnt have information, Resolver can directly check with name server rather than checking with Rserver and TLD.

    Reply
  31. Soumyadeep Roy Post author

    I get it but if you cache every unresolved domain names,the cache would be very large,isn't it ?

    Reply
  32. tortuga paradise Post author

    Say I want to know more about a girl in my class …
    RESOLVER = myself..
    ROOT DOMAIN = my best friends whom I ask for help and redirects me to the people who can help me
    TOP LEVEL DOMAIN = My besties friends who are pro at flirting to a particular group
    NAME DOMAIN = The Girl's friends group to which I get introduced by the flirty friend…
    ….
    ….
    comon dude ::: Just look her up in social media …. STALKER ..!!!!!

    Reply
  33. Important Tech Bangla Post author

    Dear sir, i am from Bangladesh. I want to your whatsapp number

    Reply
  34. Jarrod C Post author

    Why does it go through so many servers, why not directly to the ANS?

    Reply
  35. Chavdar Zakev Post author

    I have a question and I hope you can help me.
    I'll use analogies.
    Suppose Bill manages a three-team football championship (A, B, C), each team consisting of 10 players.
    A manager is assigned to each team and each manager and player has a phone number (if needed for contact puposes).This information is listed on List A, List B, and List C.
    If someone wants to contact player 5 of team A, he or she contacts Bill and Bill contacts the team manager of the team from which receives the telephone number.
    If I understand correctly Team A is the domain name, such as easyflare.com, Bill is the DNS, the players are the records( such as a webserver), the whole team is the zone files, and the managers are….
    I don't know their purpose. Are they Administrators, TLDs(it is related to the parent-child relationship in the domain name structure), another kind of DNS.
    Thanks in Advance.

    Reply
  36. Tiru International Public Speaking Tutor Post author

    A Very Complicated topic made very simple by you .

    Reply
  37. Eugene Pohjola Post author

    Howdy.

    Name Type Scope Features

    NetBIOS peer-peer LAN Not TCP/IP originally
    NetBEUI peer-peer LAN Enhanced NetBIOS
    WINS client-server LAN NetBEUI
    WINS over TCP/IP client-server LAN TCP/IP
    DNS client-server Internet TCP/IP

    Regards.

    Reply
  38. casper nielsen Post author

    Can someone explain to me, when the TLD server gives back the address of the authorative name server, in this case "NS54.WORLDNIC.COM", how does the Resolving Name Server know the IP address of this server?

    Reply
  39. Ankit Raj Post author

    Legendary video. It just clear everything in one shot.

    Reply
  40. MetalHead DS Post author

    The analogy of DNS == 'Phone Book' actually a really good example. Thank you

    Reply
  41. Tamil Student Post author

    Who keeps those root, top level domain, and name servers in the world?

    Reply
  42. Jake Brown Post author

    Great info! I've been looking for a channel like this (Y)

    Reply
  43. Maurice Walker Post author

    Very interesting information. There were things l did't know about.

    Reply
  44. condor5635 Post author

    so what do the root server and TLD bring to the table other than ultimately directing you to the Authoritative Name Servers? why not go directly to the ANA? They seem to be useless but i am sure there is a good answer. great video

    Reply
  45. Zhengguo Sun Post author

    Can some one explain
    Why can't the TLD link be skipped? it seems like an extra step to me .
    Thanks

    Reply
  46. Hurali Akhila Post author

    Sir u explained good 👌 upload vedio what r the drawbacks of dns?

    Reply
  47. cam85twin Post author

    This is excellent source for computer science knowledge

    Reply
  48. Raphael Cramer Post author

    So, basically an internet search is a state-owned company with its bureaucracy, but 300 million times faster

    Reply
  49. JACK CHEUNG Post author

    So why don't computers ask the name servers in the first place???

    Reply
  50. Rubini R Post author

    its very easy to understand and can we get the IIS topics

    Reply
  51. RedaMalaga Post author

    Amazing video and amazing explanation! Thank you very much! ***

    Reply
  52. Herbie M Post author

    Poor resolver going through all that hassle just to get one simple Yahoo IP address, just fckn google for it 😀 I mean, how long does it take to go through all this steps, all the cables and routers and under the ocean wtf?

    Reply
  53. Cristian Micu Post author

    so why the resolver doesnt cut the red tape and go directly to the authoritative name server, since those 2 bums dont know

    i also have a switch question if i have an 8 port switch, that means one of the 8 ports are used to connect to the router and the other 7 ports to connect to the client devices for the switch , right

    Reply
  54. Carlos Seminario Post author

    Thanks so much for your videos, they are awesome. The explanation you give is phenomenal!!

    Reply
  55. born ultimat Post author

    and I was wondering why loading a webpage is taking so long xD

    Reply
  56. Niferno Post author

    i bypassed the administrator privileges block in my school DNS and am probably in a shit tonne of trouble if they monitor it, (which the probably do.)

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *