Meaning and operation of IP address

Laptop, phone, tablet, camera or any device that is connected to an Internet or LAN, has a unique identification address. This address represents one device so that other devices can communicate with each other. This address is called IP - Internet Protocol.

If you're a long-time internet user, you're using internet-enabled technology devices, you've seen a number like this: 192.168.1.34. Of course for the majority of users, they don't need to care about the above numbers, it has been handled by the operating system itself and does its jobs automatically, you just need to make sure you are connected to the internet is to be. However, if you really want to understand more about IP, then continue to follow it later.

The IP address represents a device so that other devices can communicate with each other.

So why do you need to understand more about IP? Simply if you want to fix network connectivity problems yourself, know how to store or retrieve data from one computer to another, install a shared data storage server for the family . then You need to know about IP, besides IP is also very attractive, you can increase your knowledge.

In this article, internet-connected devices including phones, computers, tablets . are collectively referred to as computers.

Note: the article only provides the most basic information about IP addresses for non-IT professionals to understand, and the higher technical information will not be mentioned.

So, what is an IP address?

According to Wikipedia, IP Address (IP stands for English word: Internet Protocol) is a unique address that electronic devices are currently used to identify and communicate with each other online. computer using Internet protocol.

Each IP address is unique in the same network level.

A simpler way: IP is the address of a computer when participating in the network to help computers transfer information to each other accurately, avoiding misplacement. The IP address in the computer network can be considered the same as your home address so postal workers can give you the right letter, not someone else.

IP - Internet Protocol address - Internet protocol.

IPv4 addresses are usually written in the form of four decimal places, separated by dots, type 192.168.1.34. Since 32 bits are equally divided into four numerical groups, each group will consist of eight data bits, often called an oc-tet, ie a binary 8-bit set. For this number of bits, the value of each oc-tet will consist of 2 ^ 8 = 256 values ​​between 0 (eight bits full 0) and 255 (eight full bits 1). So with decimal address 192.168.1.34, changing to binary would be 11000000.10101000.00000001.00100010. Computers only work with binary numbers, so this is just an IP range for a computer to understand, for ordinary users, there is no need to care about this number.

Two components of an IP address (here only refers to network class C)

Composition of IP address.

An IP address is divided into two parts:

Network ID: includes the first 3 sets of numbers, Network ID is used to determine the network to which the device is connected. The example is only 192.168.1.34, the Network ID is 192.168.1., Meaning all devices have the same network layer 192.168.1. will communicate with each other. IP addresses outside the network will not be able to communicate to addresses in that network.

Host ID: is the last set of numbers, used to determine the correct address of the device. For example, with the address 192.168.1.34, the Host ID is 34. In a network 192.168.1. , there will be 1 to 254 Host ID sets, corresponding to the number of connected devices.

Understandably, in an intranet, Network ID is the name of the road, in this path there will be many Host IDs that are house numbers. So to find a house in Da Nang, you just need to know the name of the road (Network ID) and the house number (Host ID).

Subnet Mask

Each IP address comes with a component called Subnet mask. Because the TCP / IP protocol defines two IP addresses that want to work directly with each other, they must be on the same network, or the same Network ID. A subnet mask is a 32-bit set of IP addresses, but it is characterized by dividing into two regions, the left-hand area is full of 1 bits, and the right-hand area is full of bits. corresponding to the 1 bit region of the Subnet mask called the Network area of ​​that address, the 0 bit part is called the Host ID.

Subnet Mask specifies the network layer of an IP address.

For example, with the address 192.168.1.34, in the network configuration section, we will configure the Subnet Mask as follows:

192.168.1.34 - Network ID. Network ID. Network ID.Host ID

255.255.255.0 - Network ID. Network ID. Network ID.Host ID

There are three standard Subnet masks 255.0.0.0 for Class A network addresses, 255.255.0.0 for Class B network addresses, and 255.255.255.0 for Class C network addresses. In the above example we are use class C, more popular.

In short, Subnet Mask defines the network layer of an IP address, so that two devices can communicate with each other, it needs to be configured with Subnet Mask.

What is Default Gateway?

Default Gateway is the address of your home router.

The TCP / IP protocol also stipulates that two IP addresses with the same Network ID can send information directly to each other. For example, 192.168.1.34 and 192.168.1.35 with the same NetID as 192.168.1.0 should send information to each other simply, because in the same network.

In case two IP addresses have different Network IDs, for example, 192.168.1.2 with Network ID is 192.168.1.0, and 172.16.4.2 has Network ID of 172.16.0.0, they want to send information to each other. by the router, by sending out a default exit port, Default Gateway is the router's IP address.

In the home computer network, the normal client addresses are 192.168.1.2, 192.168.1.3, 192.168.1.4 ., when you want to send and receive information out of the Internet, are any IP addresses, sure To have Network ID different from 192.168.1.0, you must send the Default Gateway address to 192.168.1.1. This IP address 192.168.1.1 must be installed on the family's ADSL router. This also means that a home computer that wants to connect to the Internet must send information to the ADSL Router, and the device will redirect the packet to the destination.

So, Default Gateway is the address of your home router, the address when you want to access a website, the information you request will be sent from your computer to the Router's Default Gateway, then Then Router will send this information out of the internet to download that website and return it to you.

what?

You've probably heard "changing DNS Servers" to access Facebook, so do you know what DNS Server is?

When you visit a website, such as facebook.com page, ., all the above sites are identified by IP address. But for an end user, you can't remember all the IP addresses of each site, so DNS was born.

DNS is an acronym in English for the Domain Name System, which is the name resolution system . As the name suggests, it is responsible for resolving domain names into IP addresses so you can access a website.

So why is DNS Servers called? Because the DNS system is installed on a server system, by many different providers. Back to the question of why to change DNS server to access facebook? Quite simply, if you leave the DNS Server by default, that DNS Server will point to the Internet provider 's domain name resolution system for you, for example, VNPT network. And that VNPT network will not resolve the facebook.com domain name via IP address to prevent you from accessing facebook. So, how to fix it, you simply need to change DNS Servers via Google's server (8.8.8.8), Google's DNS Servers will help you resolve the domain name facebook.com via IP, and you will access normally.

The difference between IPv4 and IPv6

The IP address we for example are now IPv4 addresses developed in the 70s. IPv4 is only represented in 32 bit binary form, so it will provide more than 4 billion different IP addresses. It sounds like a lot, but now the number of IPv4 addresses is running out, the world has been switching over to IPv6.

IPv6 with 128 bit binary, providing more than 340 trillion trillions, trillions of addresses (2 caps 128), an infinite number that we cannot use, so we will no longer have a lack of addresses IP again.

IPv4 displays addresses as 32-bit long strings written in decimal format, such as 207.241.148.80 or 192.168.1.1. Since there are trillions of IPv6 addresses, they are written in hexadecimal like 3ffe: 1900: 4545: 3: 200: f8ff: fe21: 67cf.

How does a device have its own IP configuration set?

You will probably realize that even though I have not configured the IP address for my phone or computer, it is still in the internet and has a private IP address. That's because your device is in active IP receive mode, now let's learn a little more about dynamic IP and static IP.

Change IP address.

As in the picture you see there are 2 options:

• Obtain an IP address automatically : Here your device will automatically receive the IP configuration via a system called DHCP (Dynamic Host Configuration Protocol). DHCP is configured in your home router, when a device connects to the Internet, DHCP sends a set of IP information to help your device connect to the network without you having to do anything else. Note that every time you access your home network again, the IP address will change through a new address.
• Use the following IP address : here you will configure your own IP address, and it will not be changed when the connection is disconnected. This is useful when you want to make a storage system on a fixed computer, with a fixed IP.

So, complete the basic knowledge of IP, hope you understand and will fix the problems that you encounter when connecting to the network.