What is DNS?

Question

Computer networks

Can you explain to a newbie what it is? With sites, the matter is clear, this is a URL:IP table. But from a PC on the network, I don’t understand nicherta. Why does my IP need another DNS? What does this DNS also have some kind of IP. And even the network has DNS. Who assigns it to my PC? Why is he? The more detailed, the more interesting it will be for me to read, although of course everyone is too lazy to write a lot.

Answer 1

I'm a little exaggerated, but I'll try to explain. Computers on a network communicate with each other using IP addresses. Moreover, the networks are separated from each other and communicate through nodes connected to several networks (routers). And in all networks there is a certain hierarchy of addresses so that there is no repetition of addresses. When you connect a computer to a new network, it's obvious that you need to get a valid address on that network. In the settings, turn on the DHCP protocol, the computer sends a request to the network, and if there is a DHCP server on the network, it will return the network settings (IP address, network mask, default gateway and DNS servers).
IP address - which you must assign to yourself and respond to it.
Netmask - shows the characteristics of the network, including its size.
The main gateway is a computer for accessing neighboring networks and, in general, for all traffic that is unknown to you. It's just the router.
DNS servers are a set of IPs from which you need to ask for the IP address of a certain domain. There is no other sacred meaning in them, only the translation "domain -> IP". Without DNS, only using IP, there is no way to do this.
DNS servers, in fact, you can choose any. The main thing is that they answer you the truth for your network.

Answer 2

Have you been banned from Wikipedia?
http://en.wikipedia.org/wiki/DNS server

Answer 3

The IP address of the DNS server on the local network (as I understand it, the provider's one), is the address to which DNS queries are sent from your machine. The provider's DHCP server gives it to you (or it is manually set for especially poor providers). You can use any other alternative DNS server, for example, Google's 8.8.8.8, but then most likely access to billing, local network resources and other intranet sites will be only by IP address.

Answer 4

You are incredibly lazy. Applause.
And how does your computer know which DNS server to connect to in order to resolve the host into an IP address? Here it is indicated (usually several for reliability)
Either manually or automatically using the DHCP dynamic network configuration protocol. Vobshchem appoints the provider. There is a frequently used dns from Google - 8.8.8.8 and 8.8.4.4

Answer 5

DNS computers do not need, they communicate with numbers. But it just so happened that the human brain remembers names / words much easier than sequences of numbers. For this, they came up with a system of Internet names (domain names).
Essentially, DNS is a distributed database. There are root servers, they know who is responsible for the first-level zones (ru, com, org, etc), the first-level domain servers already know who is responsible for the second-level domains (site.com, example.ru, etc.) .) etc.
All this is necessary in order, roughly speaking, to type in the address bar of the browser not "http://164.231.29.32/index.html"/, but "http://porn.com"
Short video explaining the work of DNS (alas, without translation into Russian, but everything is very simple and clear there)