How DNS Works Visually

/ thesimpengineer
/ schachte
Visual guide on understanding how DNS (Domain Name System) works when making requests on the internet. In this video we will understand:
- DNS
- Recursive resolvers
- TLD top-level domain name
- IANA root nameservers
- Authoritative nameservers

[@t7d5]

I never comment on videos but holy shit man, I've been looking for a clear visual representation for 2 days now and your video finally explained it to me in a way I actually understand without skipping anything. Thank you so much! You are amazing :)

[@tomelam]

The basics of DNS (not the details of the protocols or formats of packets or such minutiae) seem so simple to me that why they have eluded me all these years could only be due to my laziness. However, having been bitten by the problem with my subdomain, I thought I’d look for a clear and succinct explanation and found one: How DNS Works Visually - KZbin I know, I know. I should learn this by reading. However, it’s actually faster for me if I watch a video with good diagrams and good narration. If the video is on KZbin I typically speed it up by a factor of about 1.5 to save my time. Near the end of Ryan's video, the schematic diagram of the flow of data between the client and all the servers encapsulates the key points beautifully.

[@jessiz-]

This is great, loved the clear and clean visual presentation - it's exactly the level of detail I was looking for. Thanks!

[@xanvong1501]

Thank you ! Very well explaining with graphics. It is easier to capture the information!

[@unsureofname0]

This was amazing, especially the end explanation. I really appreciate it!

[@picopita]

THE best video on DNS - explained so clearly. Please keep making IT videos.

[@AhmedSalama-mg6gu]

Very clear , simple and easy to understand . Keep the good work ryan

[@darccau7204]

Thanks for explaining, for me DNS is one of the most complicated network services to understand, and you make me understand

[@EpicAOEsRealm]

Thanks for all the work you put in your videos!

[@Dave-dl8ey]

this is an awesome video and explanation! Thank you Ryan

[@collinxsmith]

very clear and informative! Thank you. I didn't know the flow went past the root name servers, them being called "root" and all haha. I wonder who manages the TLD and authoritative nameservers?

[@navneethegde5999]

Amazing explanation! and great presentation

[@AmongUs-qt3uo]

thank you so so so much man! This is the greatest video on how DNS works! thank you so much!

[@azizulhakim1534]

Amazing explanation! Thanks for the video sir.

[@classover4128]

Thanks for your work. It's impressive!!! Love from China!

[@MS-mq4gd]

Very Clearly and Neatly Explained...#love from india

[@Ella15745]

pretty clear explanation - thank you!

[@AtulDislay]

Brilliantly explained 👍

[@stronggarner66]

Great breakdown!!

[@storaman12]

Excellent explanation.

[@eis3nheim]

Great explanation, Thanks!

[@andrewprasanna9323]

Very well explained!

[@joaoleonardolemos9078]

Very nice explanation!!!!

[@nvasudeva]

Awesome ! Very well explained !

[@MrLordSeong]

Honestly, it makes it much more clear when you put the whole thing in one pic instead of dividing it into multiple sections explaining each concept like the others.... Thanks you sir

[@thesmartest1919]

thanks, very clear explanation

[@just_some_bigfoot_hacking_you]

Some ppl are still confused why we have many DNS servers. And so why we have so many DNS servers? Simple, to avoid single point of failure. For example, just imagine when we only have one server. What if that server failed, who's gonna back it up? Imagine if Google's own server failed, or any network just for reference. That's how and why network engineers came up with multiple servers. And basically, when you only have one server, just imagine the struggle how it will handle the load of traffic. And having multiple server architecture also grants better security.

[@pilotwasif]

Good job nicely explained.

[@saranyan938]

Well explained, Thank you.

[@mahdideveloper1794]

thnak's for the explanation simple and clear : )

[@andrew.schaeffer4032]

Love it, thanks. I'm def. A visual learner

[@silverwar779]

Thanks for the explanation, you should make for videos like this

[@jnelly3426]

Very well explained

[@Tortuex_]

thank you so much ! super clear !!!!

[@cdb7700]

Thank you very simple

[@adamyerima5254]

great explanation

[@gustavomuller7190]

Great video!

[@andradegilmar]

This video deservers 1000 likes

[@RT-kk2gk]

Excellent!

[@tom0ocadoo]

so good thanks

[@thomash7247]

Thanks !

[@vibhors]

NICE ❤️

[@glitchedmatrix1962]

best video

[@Aditya-ns9qh]

Thanks for this video..couple of questions. Can root server cache DNS records and reply back to the recursive resolver? if yes what kind of records are cached in root servers?

[@KimaniWaNdirangu]

I "essentially" enjoyed this DNS video.

[@ntrgc89]

How do the domainIP address mappings appear on the nameserver? And how does the TLD server become aware of the authoritative nameservers? I've set up sites with GoDaddy before, and I know I've created something like an A record or something like that. Is goddady essentially one of the authoritative nameservers?

[@DennisKarlsson]

You can set up your own nameservers. For that you'll need glue records on the registrar.

[@tepidrachet95]

Hey, thanks for the explanation! Clear and informative. A few improvements I would suggest to make it clearer and easier to follow: 1. Your images work well along with the explanations you give, but I think you could take a bit more care in how they are laid out. For instance at 7:00 in the video, your diagram has become quite complicated and there are lots of lines which cross over other lines; it's tough to remember what was happening in the early stages if the lines are obscured by the later parts! Another example: at 10:20 your arrows are a bit all over the place, making it hard to tell at a glance what order the requests/responses are sent. 2. You stumbled once or twice in your explanation, and I also noticed a lot of filler words/phrases, eg 'Essentially', or 'What's known as'. Most of the time these don't really add anything (It's not 'essentially' Google's homepage, it IS Google's homepage). Maybe you could try writing down what you're planning to say first and then reading it as a script - this will make it easier to streamline your explanations a little (and make the video shorter and clearer). 3. Some minor graphical glitches, eg the numbers for your steps aren't centred very well in their boxes. Small details but it was a bit of a distraction for me! Enjoyed the video, looking forward to seeing more :)

[@TheSimpleEngineer]

Thanks for the valuable feedback!

[@eatfruitsalad345]

enjoyed the video! couldn't help but wonder: would typing in some nonsense URL like asdfkljasdoifj.com trigger all the steps you outlined in the video? or would it resolve at an earlier step?

[@vinayak186f3]

Thanks

[@hellokittybg93]

Hey I have a question, I'm newly employed as technical support agent for an ISP, but I'm struggling as I'm not tech savvy lol. As we were explained that sometimes we need to switch customers to google's dns instead of our own (i guess that would be the resolver server from your video) if they have issues with accessing certain websites, my question is why is that really necessary if both resolver servers are going to reach to all the other ones you mentioned until they find the ip address of the website in question?

[@armeli]

Simple explanation would be that not all DNS-servers are equal. Some respond faster and have larger cache. Also by changing the DNS address of the client device you can make sure whether the ISPs DNS server is actually working correctly. Ideally every DNS server should resolve any domain, but unfortunately that is not always the case because of configuration errors etc. That being said I am an ISP tech support as well and during the last 10 years I have never had a situation where I had to do this sort of a check. Mainly because if the ISP DNS server does actually have a problem it should be known almost instantly. Personally I use a third party DNS server just because there are way faster DNS servers available than the ones typical ISP's host.

[@hellokittybg93]

@@armeli this clears things out, thanks!

[@Raymondgogolf]

@@hellokittybg93 Hi Aqua I hope my comment didn't sound as a form of privacy invasion your comment tells of a wonderful man with a beautiful heart which led me to comment I don't normally write in the comment section but I think you deserve this complement. If you don’t mind can we be friends? Thanks God bless you….

[@MsAshutosh123]

what if the resolving query fails or root server does not know were to get the IP information..Will it ask other DNS servers to get the information and route further to TLD or AN Server

[@netwizard7920]

10 / 10 like

[@zacharykosove9048]

Which step does DNS adblocking happen if I were to use something like NextDNS

[@mrmuffin5046]

the only thing missing from this video is not mentioning the dns records as you were explaining the flow. you should have included, A records, cname etc...but amazing video

[@fadhilh3931]

What the reason to make a lot of nameserver? Can they just put the TLD in Root? So it way more faster to get the IP address

[@blasttrash]

Nice video. Thanks but one question. Why does Root nameserver(A-M or whatever) again return back ".com TLD" when I specifically requested for .com(i.e., google.com)? Why waste unnecessary round trip? Can't we directly go to .com nameserver itself? Why do we have to go to root nameserver which tells us the information that we already know(in this case that the user wants to go to .com or google.com)?

[@TheSimpleEngineer]

Great question. There are currently 13 managed IP addresses for root nameservers (load balanced across far more physical instances around the globe).These IPs rarely change and are often shipped with software that you use, like recursive resolvers. The underlying list of IPs for TLDs is far larger and has a greater probability to change, therefore making it much harder to manage over time. Root nameservers help resolve the dynamic nature of the TLDs by getting updated lists, which is a process completely abstracted from the end-user. It's also important to note that caching plays a huge role, so speedup is often negligible since you're hitting the cache the majority of the time. (IE root zone NS records have a 48 hour TTL). Short answer.You can cache TLDs locally, sure. This becomes a problem in both DNSSEC from the perspective of ensuring authenticity of the requests as well as having to now manage the random changes occurring with TLDs. Cheers!!

[@gunnargu]

The root name servers aren't the ".com" servers, they are the "." servers, they serve the "root" of the domain name hierarchy, a little known fact is that all domains have a hidden "." at the end, so "google.com./" is the same thing as "google.com/", it's just that all clients hide the root.

[@zizzu549]

@@gunnargu Ahah, so you have to read the name in reverse ^^ and the dot at the end are the root servers. Now i understand where that dot comes from when i read the bytes of dns responses when i trace syscalls. This image helps: en.wikipedia.org/wiki/Fully_qualified_domain_name

[@blasttrash]

@@gunnargu yeah thats what I meant. I only referred to A-M as root servers while I called the other ones as ".com" nameserver(for lack a better word). Is there a specific name for ".com" nameserver just like how we call A-M as "root" nameserver?

[@AaronPlattner]

@@blasttrash yeah, they're a through m.gtld-servers.net. You can query that from the root servers by doing an NS (i.e. "nameserver") query for "com." This site lets you do that. Change the query type to "NS" and enter "com." as the domain name to query. www.dnsqueries.com/en/dns_query.php

[@ardomainaky]

prolog part 5 pls

[@tenminutetokyo2643]

DOOD!

[@GrigoreCIMPULESCU]

Good video, but you missed a step, you forgot about the hosts file.

[@anldursun8300]

I'd expect a better explanation of how TLD identifies the authoritative server.

[@reanibutani9555]

Make new video

[@Raymondgogolf]

Hi Rea how are you doing

[@EmilFihlman]

"DNS Name Server"

[@MrMadan306]

Happens.. but his explanation was really simple and neat

[@henrykorvus6954]

Too long.

[@jessewright870]

Excellent!

[@tzuyulk]

Thanks!