What is an IP address and what is it for

What are IP addresses, what are they for, how they are assigned, and what information we can extract?

IP address
The computer’s IP address is the number that identifies it on the network when you visit websites, in the same way, that a postman finds the address of a home. In general terms, two computers communicate with each other through their IP addresses, so the IP address is therefore necessary for the server computers hosting websites to know where to send their data.The reason why it is important to know what an IP address is is not only cultural, but also very practical, to solve problems with the network and with the internet and, above all, to understand if our privacy is at risk or, in others words, if anyone can know who we are and where we are in the world using the IP address.
Given the technical vastness of the topic, this is a very simplified summary article that leads us to understand what is an IP address broadly, what is it for, and, above all, how important it is for privacy.

What is an IP address?

  • What is an IP address?
  • Types of IP addresses
  • How computers are assigned IPs
  • What can be found out from an IP address
  • Check what websites you visit to know about us from your computer’s IP address
  • The IP addresses of the websites
  • How does the police find a person’s address from the IP or site visit?
  • How to hide an IP address
  • Find out an IP address

What is an IP address?

IP stands for “Internet Protocol“, so the IP address is an address from which the computer sends and receives data. As mentioned above, you can think of IP addresses as street addresses of the Internet country.
The IP addresses of computers are made up of numbers and every site, computer, or server in the world, when it connects to the internet, is assigned an IP address, random or fixed by the person who manages it.
When you go to upload a website to Chrome, your computer sends a request to the IP address of the server where the website is located and downloads its content. The website then sends its content to the PC using the computer’s IP address.
The operation is very similar to sending a postcard to someone, on which you write your home address so that the postman can deliver it correctly.

Types of IP addresses

IP addresses are of two types:

  • IPv4 addresses: the version used since time immemorial and still very widespread; this form of IP is made up of 4 sets of numbers ranging from or to 255, for example,
  • IPv6 addresses: the most recent but still not widespread version, made up of 8 groups of 4 hexadecimal digits (the rules are much more complex).

IPv4 addresses are assigned both by internal networks (in the form 192.xxx.xxx.xxx) and by Internet connections: in fact, every Internet user (both site and connected device) connects by assigning an IPv4 address. Since this type of address has been exploited for all Internet sites and for all connected devices, they are now exhausted: new IPv4 addresses cannot be assigned to navigate; to solve this problem, the use of IPv6 addresses is becoming more and more widespread, which are much more numerous and will take many years (probably decades) before ending use.
For the average user, nothing changes: whether it is IPv4 or IPv6, he will still surf the Internet without problems; things change if we have to forward the modem ports or we have to configure a home server since we will have to memorize a numeric string much harder to remember with IPv6.

How computers are assigned IPs

Computers on the internet differ from each other in two broad categories, clients and servers.
Servers are computers that share resources on the network or on the internet, clients are PCs or smartphones that connect to servers to download data or view websites (in the case of web servers). The servers have a fixed IP, the home PC and the smartphone, on the other hand, have a dynamic IP that is assigned by the router.

When paying for an internet subscription, the provider assigns an IP to the subscriber which can change dynamically.
The router, also functioning as a server DHCP (Vedi ala DHCP guide to assign IP manually or automatically), assigns IPs to computers to go to the internet and then, via technology NAT (Network translation technology), manipulates them so that even if the internet provider changed the assigned IP, there would still be no problems. As seen, some telephone companies allow you to activate the fixed IP (for example see how to ask Fastweb for a fixed public IP for free) so that you can use it for server applications on your own computers. The IP assignment discourse is very complex because when only IPv4 existed, these were numerically limited for all computers in the world and network managers had to find conventions and tricks.

We had talked about this in more detail, in the article that explains how we connect to the internet and why with the same Public IP.

What can be found out from an IP address

By having someone’s Internet IP address could we connect to their computer or could we know where they are? From an IP address it is certainly possible to trace its geographical origin, even if not in a precise way: however, there are two problems in this attempt to trace:

  • Client computers, those that are not servers, do not connect directly with the Internet address but are included in a subnet, managed by the modem or router. The IP address that we can publicly obtain will almost always be that of the router, while the computer we are looking for could have one of the internal IP addresses (protected under NAT or other security systems); to this, we also add that often a single public IP can be a simple one exit node, that is, assigned in a shared way to other people around the country.
  • Unlike phone numbers that have a country code, IP addresses are assigned to companies rather than countries, so there is no indication of where the numbers come from. Using tools capable of extracting information from an IP address, it is only possible to have an estimate of where the user is and to know which telephone company he uses to connect to the internet

Even if we have someone’s public IP address, we won’t be able to easily enter a computer, unless we are expert hackers and we trace the entire connection back to the single device (this is not an easy thing to do and still requires some preparation).

Check what the websites you visit know about us

To find out what information can be found about us based on the IP address of our PC that we use to browse the internet, there are some online tools. We talked about these tools in the how-to guide to find the IP address of another computer, where we reported the site Whatsmyipaddress.com, capable of telling us the origin and internet provider of an IP address.
With this site, it is possible to find out my IP.

By connecting to the site we will immediately see our IPv4 and IPv6 and it tells us which city we are in and which company we are subscribed to. Keep in mind that with dynamic IP addresses, which we mentioned above, every time the router is reset or restarted it acquires a new IP address from the internet provider (unless a static IP has been requested) then the address IP will change on the computer. Furthermore, the same IP can be shared and used in multiple homes, whether it is a VPN connection or a corporate network.

The IP addresses of the websites

As we have explained briefly, websites are hosted by servers, that is to say by computers that can be reached on the internet from all over the world. To reach a site, however, you do not have to type the server IP on the browser, but just write the site address, which is easy to remember (such as www.How2do.org).
To make sure that by typing www. google. it, the computer connects correctly to the server where Google is located, the DNS servers (Domain Name System), which use an address book by associating IPs and names. We have seen, in another article, how to get DNS servers more speed, explaining in more detail what they are. In theory, it is also possible to assign a DNS to the IP of the computer, to connect to it from the outside.

How does the police find a person’s address from the IP?

If a person commits an online crime such as threatening to kill someone via text, they can be tracked down by the Italian or other country police in two steps:

  • First, he finds out the IP used by that person by asking the site where he committed the crime to tell him, then he asks the internet provider who has been assigned that IP.
  • If the offense is of a certain gravity, then the internet provider and the site will be forced by law to provide this information

If we are under investigation then it is highly likely that we will be traced, complete with the name and surname of the owner of the offending Internet line. To get more protection (but probably not enough against the police), just read the following chapter.

How to hide an IP address

If we want to hide the IP, the geographical origin, and also the company that provides internet to our computer or mobile phone, the simplest way is to use a VPN, which disguises the IP and makes the connection appear to be coming from a different country. Through the VPN the data traffic of the computer is encrypted, it passes it to the VPN that sends the request on the website; no one, not even the telephone company, will know which site is visited by that computer. If someone tries to trace the origin of the IP, they will see the address of the VPN and not that of the computer used.
To deepen the discussion, we refer you to reading our guides on how to surf anonymously on the internet with proxies, VPNs and fake IP addresses come on how to hide IP addresses on PC, Android, and iPhone.

Find out an IP address

It is not that easy to find out the IP of another computer on the net and you need to come up with some hacker tricks to do it; but if we want to find out the IP of the devices connected to the same local network (therefore the devices connected to the same modem or router) we can use a program such as Advanced IP Scanner, available for free from the official website.
Advanced IP Scanner

Using this program we will be able to immediately discover the IP address of all devices connected to the network, including other computers, smartphones, tablets, home automation devices, printers, and also the IP address of the modem.
If we are looking for something similar for smartphones we can rely on the free app Fing, available for Android and for iPhone / iPad.

If, on the other hand, we want to find out other people’s IP addresses, in another article we showed you a trick that works for track the IP from Whatsapp, Facebook, or an Email.


While it seems so easy for us to connect to the Internet, without IP addresses this connection would not be possible or would be much messier than the current one. In the chapters seen above we learned the computer basics behind the IP address and what we can do to discover this information (on the local network and not) and what we can do to hide this personal information.

To deepen the discussion we recommend that you also read our Great Guide on computer LANs, internet, and wifi.
If, on the other hand, we fear that our network is being spied on or we have suffered an intrusion, we can also read our guide Protect the network from intrusion, wiretapping, and spying.


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