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Development Tools Technology Foundations DNS Basics Root Servers

Why would there be no internet without root servers?

Jason stated at the end of the video that there would be no internet without root servers. Surely, websites would still be accessible via their IP addresses, even though it would be very difficult.

3 Answers

(If I understand how things work...)

@Mujavid seems to be saying that since DNS is just for looking up numeric IP addresses, we might have used only the IP addresses and still have a functional internet. No need for root servers.

It would be tiresome and error-prone to type out IP addresses, but really, how often do people type URLs anymore? They mostly click on links, either from search engines that wrote the links programmatically, or from web developers who copied and pasted. And when they do type one in, they usually use a search engine instead and get there just as fast, with fewer errors. So it wouldn't even be so bad if we didn't have DNS!

Then again, people used to type out URLs more, and if they'd had to type out IP s instead, the internet might not have gotten so insanely popular so quickly. So we have to thank the root servers for making things easier for those paleolithic URL-typers.

(...if I understand how things work :) )

Lewis Cowles
Lewis Cowles
74,902 Points

The internet is a series of nested networks (set's of computers with IP's). While it is possible to run an intranet locally without root servers to co-ordinate, once you add multiple networks, you need to manage both the internal link to each network's IP, but also the name that resource relates to. In order to give named intranet addresses you either have to setup a DNS with Root name server internally (in which case the external network does not know about it), and you have used a Root name server anyway.

Coming away from tech the DNS is like the conductor, the name servers are the seating arrangements or groups. In order for them to work together they need a conductor!

Stephen Emery
Stephen Emery
14,384 Points

I could be totally wrong, but I think it works this way :)

Root servers direct network traffic. Say I typed in the ip address for google: http://74.125.224.72/ into my browser. My computer sends out a broadcast/query to find the server that will answer that address. If there was no root server, there would be no answer. Google's server would not know my computer was looking for it. Basically leaving a blank page on your computer.

If there are root servers, typing in that ip address sends out a broadcast. The root server picks it up and directs you query to Google's servers. Then you are directed to Google.com. A name server works in conjunction with the root server.

When you type in www.google.com, you query the name server. The name server looks to the root server and asks, what ip goes with google.com. The root server passes the ip address and the traffic is directed to Google's servers. You are able to reach the google.com page.

Shawn O'Connor
Shawn O'Connor
14,135 Points

Root DNS Servers do not route traffic. They simply return an IP. Internet routing is is handled by IP assignment managed and Coordinated globally by IANA. Carriers like AT&T, ETC are assigned LARGE blocks of publicly routable IP which they divvy out to their customers. These are routed using dynamic routing protocols, namely BGP or Border Gateway Protocol. There aren't enough IPV4 addresses to go around, so it gets even more complicated with NAT or Network Address Translation.

Back to the original DNS question. Without DNS, you would need to know the IP address of every site or host on the internet. When IP addresses change because of Carrier changes, or really any number of reasons, then everyone would have to update their knowledge of the IP. This is pretty unrealistic, so basically there would be no internet without DNS.