WHAT IS AN IP ADDRESS?

An Internet Protocol address is a numerical label such as 192.0.2.1 that is connected to a computer network that uses the Internet Protocol for communication. An IP address serves two main functions: host or network interface identification and location addressing.

An IP address is a unique address that identifies a device on the internet or a local network. IP stands for “Internet Protocol,” which is the set of rules governing the format of data sent via the internet or local network.

In essence, IP addresses are the identifier that allows information to be sent between devices on a network: they contain location information and make devices accessible for communication. The internet needs a way to differentiate between different computers, routers, and websites. IP addresses provide a way of doing so and form an essential part of how the internet works.

IP Address Categories and Types

Most tech enthusiasts would tell you that IPv4 and IPv6 are the two IP address types but that is not the case. Contrary to what they think, however, there are different ways to classify IP addresses and within some categories, there are even sub-categories for further differentiation.

Sounds quite complicated but once it is all laid out appropriately, it’s actually not that difficult to understand. Here is the gist of it.

Types of IP Addresses

When you get an internet plan, be it for your business or personal use, you will have two types of IP addresses: a private IP and a public IP.

Private IP Addresses

As the industry of IoT (Internet of Things) expands, more and more smart devices are joining your home network. With things like smart refrigerators, smart microwaves, and even smart toasters all needing a Wi-Fi connection, your router needs a way to differentiate between all these devices.

These IoT devices along with the regular PCs, laptops, tablets, and phones all have a private IP address assigned to each one of them. The router uses this private IP to recognize which device needs to be serviced. This also extends to most Bluetooth devices as well.

Of course, there is a way to check what is a device’s private IP address and in most cases, a way to change it. These types of IPs, however, are seldom used by a person and are mostly only needed for use by the router, thus you do not really need to know what private IP address each item has.

Public IP Addresses

As we mentioned previously, each device on a network has its own unique IP address. All of these devices, however, are included under the main public IP address for your network. It is the one primary address associated with your whole network.

The public IP address is provided to the router by your ISP (i.e., Internet Service Provider). This is the address all the devices outside your network use to recognize said network and the devices connected to it.

All of your internet activity is tied to your public IP. ISPs can determine who is visiting which sites and using the internet through the public IP address.

Dynamic and Static IP Addresses

Both dynamic and static IP addresses fall into the public IP category. Here is the difference between them.

Static IP Addresses

As the name indicates, static IP addresses typically never change, however, they can be changed with network administration. They are considered a permanent internet address, thus providing a simple and reliable way to transfer packets to and from the device. Not many users actually opt for a static IP address but there are some cases where its use is necessary such as a Hosting, , Dedicated Server.

Dynamic IP Addresses

This is the type of IP address that is usually provided to the users by ISPs. They change every time when your device is rebooted, a new device is added to the network, or the network configuration gets changed.

This solution also ends up being a more secure option than having a static IP since regular IP address changes make it more difficult for hackers to get access to your network interface. Thus, this is commonly the go-to option for most internet users.

IP Address Versions

Currently, there are two versions of IP addresses being used: IPv4 and IPv6.

IPv4

IPv4 stands for internet protocol version 4. This is the one you will see used the most. These addresses are 32-bit long and divided into four parts known as octets, each containing 8 bits. This protocol has been around since 1981 and has not seen many changes since. Despite it having 4,294,967,296 possible IP addresses, we are still running out of them to use.

IPv6

With the rapid expansion of the internet, there is a global shortage of IPv4 addresses. To combat this, Internet Engineering Task Force (IETF) has developed IPv6, the most recent version of the internet protocol, intended to replace IPv4. It uses a 128-bit addressing system, allowing for approximately 3.4×10³⁸ addresses. The actual number is a bit lower as some IPs are reserved for special use.

Here are some of the main advantages IPv6 provides:

• Faster routing
• Better end-to-end connectivity
• Easier administration
• Improved mobility features
• Superior Multicast and Anycast abilities
• More security for applications and networks

IP Address Classification Based on Operational Characteristics

There are three different types of IP addresses within this classification.

Unicast IP Addresses

This is an address of a single interface which are used for one-to-one communication. Unicast IP addresses are used to direct packets to a specific host.

Multicast IP Addresses

Multicast IP addresses are used for one-to-many communication. Multicast messages are sent to IP multicast group addresses. The packets reach multiple destinations, however, not every single one of them.

Broadcast IP Addresses

This type of IP is used to send data to all the possible destinations within the broadcast domain.

How do IP addresses work

If you want to understand why a particular device is not connecting in the way you would expect or you want to troubleshoot why your network may not be working, it helps understand how IP addresses work.

Internet Protocol works the same way as any other language, by communicating using set guidelines to pass information. All devices find, send, and exchange information with other connected devices using this protocol. By speaking the same language, any computer in any location can talk to one another.

The use of IP addresses typically happens behind the scenes. The process works like this:

1. Your device indirectly connects to the internet by connecting at first to a network connected to the internet, which then grants your device access to the internet.
2. When you are at home, that network will probably be your Internet Service Provider (ISP). At work, it will be your company network.
3. Your IP address is assigned to your device by your ISP.
4. Your internet activity goes through the ISP, and they route it back to you, using your IP address. Since they are giving you access to the internet, it is their role to assign an IP address to your device.
5. However, your IP address can change. For example, turning your modem or router on or off can change it. Or you can contact your ISP, and they can change it for you.
6. When you are out and about – for example, traveling – and you take your device with you, your home IP address does not come with you. This is because you will be using another network (Wi-Fi at a hotel, airport, or coffee shop, etc.) to access the internet and will be using a different (and temporary) IP address, assigned to you by the ISP of the hotel, airport or coffee shop.

WHAT IS RESERVED IP?

In the Internet addressing architecture, the Internet Engineering Task Force and the Internet Assigned Numbers Authority have reserved various Internet Protocol addresses for special purposes

There are a few reserved IPv4 address spaces which cannot be used on the internet. These addresses serve special purpose and cannot be routed outside the Local Area Network.

Private IP Addresses

Every class of IP, (A, B & C) has some addresses reserved as Private IP addresses. These IPs can be used within a network, campus, company and are private to it. These addresses cannot be routed on the Internet, so packets containing these private addresses are dropped by the Routers.

In order to communicate with the outside world, these IP addresses must have to be translated to some public IP addresses using NAT process, or Web Proxy server can be used.

The sole purpose to create a separate range of private addresses is to control assignment of already-limited IPv4 address pool. By using a private address range within LAN, the requirement of IPv4 addresses has globally decreased significantly. It has also helped delaying the IPv4 address exhaustion.

IP class, while using private address range, can be chosen as per the size and requirement of the organization. Larger organizations may choose class A private IP address range where smaller organizations may opt for class C. These IP addresses can be further sub-netted and assigned to departments within an organization.

EXAMPLES OF RESERVED IP ADDRESSES

IPv4

Address block	Address range	Description
233.252.0.0/24	233.252.0.0-233.252.0.255	Assigned as MCAST-TEST-NET, documentation and examples.
240.0.0.0/4	240.0.0.0–255.255.255.254	Reserved for future use. (Former Class E network).
255.255.255.255/32	255.255.255.255	Reserved for the “limited broadcast” destination address.

What is the benefit of reserving an IP address?

You can reserve an IP address in a DHCP scope to ensure a device receives the same IP address every time your server reboots and the device is detected.

DISADVANTAGES OF RESERVED IP ADDRESSES

One main disadvantage of reserved IP addresses is that each address, once assigned, is occupied by a single computer even when that computer is not in use. Since each computer needs a unique address, this limits the number of available IP addresses.