Now that China is involved in a joint project between its administration and companies like Huawei, trying to change the way IP addresses are built and how you operate with themIt seems like a good time to explain how the current ones work, the ones that have been in force since the beginning of the Internet that we know today.

The IP address, which only responds to the initials “Internet Protocol” is the identifier that carries each device that connects to the Internet, whatever the device is, at the time it is connected, as opposed to the MAC number which is the device’s own identifier even if it is disconnected.

What is an IP address

As we said in the introduction, an IP address is an identifier assigned to each device that connects to the Internet at the time of such connection. An identifier that can vary in the case of variable IPs or that can be permanent in the case of fixed IP addresses. With this IP, our device, whatever it is, will be permanently identified during navigation.

When we connect to the Internet, the protocol we use gives us a label: that is our IP

In addition, it is a mandatory identifier since it is not possible to navigate without said address. The reason is that all the websites and programs that operate on the Internet they send the data from one IP, theirs, to another IP, ours. A web page server, for example, has to know to which device to send the page that we want to visit. That is the reason that IP addresses cannot be repeated, and that they are built in such a way that they compose a path by which a piece of information manages to locate our equipment (a mobile phone, a tablet, a computer, a TV, a connected light bulb) in the vastness of devices that are on the entire planet.

The IPs are divided in turn into two large groups, the Public IPs and private IPs. Public are the addresses assigned by our Internet provider, which is usually known as ISP, and which serves to allow us to browse the Internet. But other IPs, which are assigned from our router’s doors to the center, are the private IPs. They fulfill the same function, that of identifying each device so that all can find each other, although here it will not serve us to browse the Internet.

How an IP address is built

When the IP addresses were created, it was established that they would be built in four three-digit blocks separated by a point from each other, hence it has been called IPv4 since then (as opposed to the more modern IPv6, which we already explained here) . These IPv4 addresses are 32 bits, allow up to 2 ^ 32 combinations. Or what is the same, 4,294,967,296 addresses. More than 4,000 million devices connected at the time.

From 0 to 255 with numerical base. From 00 to FF with hexadecimal base.

Addresses are built in these four blocks, which in turn have their own rule: they are three-digit numbers ranging from 0 to 255. That is, a maximum of 256 addresses per block which, when translated into hexadecimal numbering, range from 00 to FF. If we are familiar with hexadecimal colorimetry, from absolute zero to absolute white.

In these four blocks, the first three constitute the different layers of the network to which we are connected, while the last is the one assigned to our device. I mean, in a IP, we are the number 1 device in the 230.143.089 network. Since the network is built in layers, the structure would be as follows (using the same example).

230. Identifier of the main network.
143. Identifier of the first sub-network.
089. Identifier of the second sub-network.
001. Identifier of our device in the general network.

But this is only so in class C networks, since there are two other classes of IP networks that are as follows:

A class: Network.Device.Device.Device.
Class B: Network.Network.Device.Device.
Class c: Red.Red.Red.Device.

The reason is that there are networks on the Internet so complex that the devices themselves must be located by hierarchies, and everyone has their own rules As for the maximum number of numbers to use, but we will not delve as deeply at the moment as the networks that interest us are class C, which are those that affect computers, mobiles, tablets, televisions, watches and other devices that connect to Internet in a classic way.

Is it possible to know my public IP address?

As we have mentioned before, there are two IP addresses for each device that we have connected at home, a private IP and a public IP. The private one has a format similar to, since 192 networks are reserved for this use. But when we go to the Internet, our device is assigned a public IP and it is easier than it seems to know what it is at any moment.

For example, it is enough to go to web pages like to be shown on the screen that the public IP is the one we have assigned at that time. We have already explained that networks can be fixed, although they are normally variable. So in each browsing session (when we connect to the Internet) we are assigned a public IP that can change on the next connection. Visiting these pages is a good way to know what it is at all times.