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IP Addresses: Explained

From your home computer to the sprawling servers of the Internet, every device relies on an IP address for communication.

Understanding IP addresses isn’t just for tech enthusiasts – it’s essential knowledge in our ever-growing, interconnected world.

Join us as we explain what an IP address is, how it works, the different types available, and why it’s a crucial component of life on the Internet.

What is an IP address?

An IP (Internet Protocol) address is a unique identifier assigned to every device connected to a network.

This identifier, either a series of numbers, or numbers and letters, is what lets devices communicate with each other over the Internet. You can think of it as a mailing address for your computer, in that it tells other devices where to find you so they can send you information.

Without IP addresses, the Internet as we know it wouldn’t function. They’re essential for everything from browsing the web to sending emails, making all of our processes and communications possible.

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How does an IP address work?

IP addresses act as the digital equivalent of a postal address, helping data to find its destination.

When you send or receive data online, your device uses its IP address to identify itself and communicate with other devices.

This process involves several (simplified) key steps:

  1. Data packaging: Data is broken into packets, each containing the sender’s and receiver’s IP addresses.
  2. Routing: Routers direct these packets across the internet, using the IP addresses to determine the best path.
  3. Reassembly: Once the packets reach their destination, they are reassembled into the original data.

This system makes sure that your data, whether it’s an important email, a web page request, or a funny cat video, reaches the right destination and returns correctly.

Types of IP addresses

IP addresses come in several types, each serving a unique purpose. Understanding these types and their quirks helps in managing network configurations and maintaining connectivity.

Public IP address

A public IP address is assigned to your device by your Internet Service Provider (ISP) and is used to identify your device on the global Internet.

This basic address is needed for external communication and allows other devices on the Internet to locate and connect to your device.

Static IP address

A static IP address is a permanent address assigned to a device that doesn’t change, unlike dynamic IPs.

They’re commonly used for resources that need to be reliably accessible at the same address, like hosting websites, servers, or other services requiring consistent access.

Users can obtain a static IP by requesting it from their ISP, often for an additional fee.

Private IP address

A private IP address is used within a local network, such as in homes or offices, and is not accessible from the Internet.

These IP addresses allow devices within the same network to communicate with each other without exposing them to the global Internet.

Routers assign private IP addresses from a reserved range, provided by the Internet Assigned Numbers Authority (IANA). Multiple devices can share a single public IP address for Internet access using Network Address Translation (NAT).

Common private IP ranges include:

  • to
  • to
  • to

Dynamic IP address

A dynamic IP address is temporarily assigned to a device each time it connects to the network. ISPs typically use dynamic addresses to manage and allocate their pool of IP addresses.

These addresses can change with each connection, making them suitable for general Internet use.

Dynamic IP addresses are assigned from a pool of available addresses and can vary each time you reconnect to the network, providing flexibility and guaranteeing more efficient use of the IP address space.

Special IP address ranges

Certain IP address ranges serve specific roles in network communication:

  • Designates a default network and acts as a placeholder for “any network.”
  • The loopback address, used to test network configurations on the local machine.
  • Utilized for broadcasting messages to all devices within a network.

IP address classes

IP addresses are categorized into different classes to accommodate various network sizes and functions:

  • Class A: Spanning from to, this class is assigned to large networks with extensive device connections.
  • Class B: Ranging from to, it serves medium-sized networks.
  • Class C: Covering to, it is designated for smaller networks.
  • Class D: From to, this class is reserved for multicast transmissions, which are used for streaming media and other applications where data needs to be sent to multiple destinations simultaneously.
  • Class E: Numbers from to are set aside for experimental purposes and research.

IP address versions

IP addresses are available in two main versions, each with its own format and purpose. These versions are IPv4 and IPv6.

IPv4 address

IPv4 (Internet Protocol version 4) is the most widely used version of IP, and the one you’re probably most familiar with.

It uses a 32-bit address scheme allowing for approximately 4.3 billion unique addresses. This format consists of four decimal numbers, each ranging from 0 to 255, separated by periods.


Despite its limitations, IPv4 is still around today, due to its simplicity and widespread use. Techniques like Network Address Translation (NAT) help to mitigate the address shortage by allowing multiple devices on a local network to share a single public IPv4 address.


  • Simplicity and widespread adoption.
  • Compatibility with most devices and networks.


  • Limited address space, which then led to the creation of IPv6.
  • Inefficient address allocation in some cases.

IPv6 address

IPv6 (Internet Protocol version 6) was developed to combat the limitations of IPv4, particularly the lack of available addresses from the massive influx of new devices in need of IPs.

IPv6 uses a 128-bit address scheme, providing a virtually unlimited number of unique addresses.

An IPv6 address is formatted as eight groups of four hexadecimal digits separated by colons, making the pool of potential addresses drastically larger, and able to accommodate the billions of devices in need.

Example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334

The transition from IPv4 to IPv6 has been gradual, with many networks and devices now supporting both versions through dual-stack implementation. However, full adoption of IPv6 is still ongoing.


  • Incredibly large address space, eliminating the risk of address exhaustion.
  • Improved routing efficiency and security features.


  • Slower adoption due to the need for compatible hardware and software.
  • Complexity in transitioning from IPv4 to IPv6.

How to look up an IP address

Looking up an IP address can provide valuable information about the domain or network associated with it. Here’s how you can gather data about an IP address:

  • For General IP Information (WHOIS):

Windows, Mac, Linux: Use the command whois [IP address or domain] in the terminal or command prompt to retrieve details about the IP address, such as the owner of the domain, contact information, and more.

  • For Local IP Addresses:

Windows: Open Command Prompt and type ipconfig to see your local IP addresses.

Mac: Open Terminal and type ifconfig to view your local network interfaces and their IP addresses.

Linux: Type ip addr show in the terminal to list all network interfaces and their IP configurations.

  • For External IP Routing Path (Traceroute):

Windows: Use tracert [website or IP address] in Command Prompt to see the path packets take to reach an external IP address.

Mac/Linux: Use traceroute [website or IP address] in the Terminal to view the route packets follow to a specific destination.

By correctly using these tools, you can gather comprehensive data on both the network routing and registration details associated with an IP address.


In summary, understanding IP addresses is like having a master key to the Internet. They’re the unseen magic that lets our devices talk to each other, making the Internet work as intended.

Whether you’re troubleshooting or optimizing your network, knowing about IP addresses is a game-changer for keeping your digital life running smoothly.

Dive into tools for managing and looking up IP addresses, and you’ll master the art of maintaining a robust and secure network.

Tip: Do you want to monitor your devices with ease and clarity? Check out our ping monitoring services, and get 50 monitors for free!


Want more? Have a look at the answers to these common questions.

How can you hide your IP address?

Hiding your IP address can be done in a few ways:

  • Using a VPN (Virtual Private Network): A VPN masks your IP address by routing your Internet traffic through a remote server.
  • Proxy servers: These act as intermediaries between your device and the internet, hiding your IP address from the websites you visit.
  • Tor Network: Tor anonymizes your Internet activity by bouncing your connection through multiple servers worldwide.

What is IP Spoofing?

IP spoofing is a deceptive technique used by cyber attackers to impersonate another device’s IP address. This is often done to gain unauthorized access to networks, launch distributed denial-of-service (DDoS) attacks, or mask the attacker’s true identity. The technique involves altering the IP packet header to make traffic appear as if it is coming from a trusted, legitimate source.

DDoS amplification is a potent type of DDoS attack that leverages IP spoofing to enhance its impact. In these attacks, an attacker sends a small amount of spoofed traffic to reflector servers which, unaware of the spoofing, send a disproportionate amount of response traffic to the targeted IP address. 

This is known as amplification. Common protocols that are vulnerable to DDoS amplification attacks include DNS, NTP, SSDP, and LDAP, all of which can be exploited using UDP. These protocols, when abused, significantly increase the volume of traffic directed at the victim, overwhelming their resources and leading to service disruptions.

Should you use a VPN? Is it useful?

Using a VPN is highly recommended for protecting your online privacy and security. A VPN encrypts your Internet connection, protecting your data from eavesdroppers and hackers.

It also allows you to bypass geo-restrictions and access content that may be blocked in your region. For businesses, VPNs are essential for securing remote work connections and protecting sensitive information.

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Written by

Copywriter | LinkedIn

Diana Bocco is a writer specializing in turning SaaS jargon into snappy, marketable content. As a freelance writer and copywriter, she's teamed up with some of the coolest brands in the SaaS, B2C, and marketing sectors, including UptimeRobot. Diana's specialty? Taking a brand's story and expertise and shaping it into content that drives traffic, generates valuable leads, and builds a tight-knit community.

Expert on: DevOps, Domain monitoring, Keyword Monitoring, Ping Monitoring, Port Monitoring, SSL Monitoring

Our content is peer-reviewed by our expert team to maximize accuracy and prevent miss-information.

Fact checked by Alex Ioannides

Head of DevOps | LinkedIn

Alex is a seasoned professional with a natural knack for problem solving. He is currently serving as the Head of DevOps at itrinity, where he oversees the operations of all portfolio products, namely UptimeRobot, Mangools, EmailListVerify, and WarmupInbox. His role involves ensuring the seamless operation and ongoing improvement of these platforms.

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