What Is an IP Address? The Unique Identifier for Every Device Online

An internet protocol (IP) address serves as the unique numerical identifier for every computer, smartphone, or device connected to the global Internet. IP addresses operate in many ways like mailing addresses – they allow for sending and receiving data across the vast network of routers and servers that enable communication.

But what exactly are IP addresses, how do they work under the hood, and what privacy concerns should you be aware of? This comprehensive guide provides an in-depth look at everything about IP addresses, including how they function, the security risks associated with them, and how you can best protect your online identity and data.

The Fundamentals: What Are IP Addresses?

An IP address is a sequence of numbers separated by periods that identifies a specific device during communication between two or more devices over the internet.

IP addresses work using a unique system known as packet switching. When you request data from a website or server, your device divides the data into small chunks called packets. These packets contain the sender‘s and recipient‘s IP addresses in their headers.

Routers throughout the internet use these IP addresses to efficiently route packets to their final destinations, where the packets are reassembled into their original data.

When you connect to your home or office internet network, your internet service provider (ISP) assigns your router or modem a public IP address. This allows you to communicate and send/receive data over the public internet.

Meanwhile, your router gives each device on your local area network (LAN) a private IP address. These private IPs differentiate devices locally and aren‘t visible to the wider internet.

IP Address Versions: IPv4 vs. IPv6

There are two primary versions of internet protocol in use today – IPv4 and IPv6.

IPv4 (Internet Protocol version 4) dates back to the early days of the internet in 1983. It uses a 32-bit address scheme that allows for over 4 billion possible addresses.

At the time, 4 billion addresses seemed sufficient. However, the exponential growth of the internet, smartphones, and other connected devices means the world has essentially run out of new IPv4 addresses.

IPv6 (Internet Protocol version 6) was developed in the 1990s to solve the shortage of available IPv4 addresses. It uses a vastly larger 128-bit address format.

To put the scale into perspective, IPv6 supports approximately 340 undecillion addresses – that‘s 340 followed by 36 zeros! This ensures we won‘t run out of addresses for the foreseeable future.

Slowly but surely, major technology companies and internet service providers are transitioning their networks and devices over to IPv6. Most modern computers and smartphones now use both an IPv4 and IPv6 address when connecting to the internet.

According to Google, approximately 30% of users accessing Google services now use IPv6, up from around 20% a year ago. However, IPv4 remains the dominant protocol powering the internet, presenting challenges for this gradual transition.

IPv4 uses 32 bits for IP addresses while IPv6 uses 128 bits, allowing for exponentially more addresses. (Image source: Cloudflare)

IPv4 Address Classes

To optimize allocation when IPv4 was originally rolled out, its over 4 billion possible addresses are divided into five address classes:

• Class A – Supports 16 million hosts on each of 127 networks. Class A addresses start with a 0 and are used for large organizations.

• Class B – Supports 65,000 hosts on each of 16,000 networks. Class B addresses start with 10 and are used by medium-large organizations.

• Class C – Supports 254 hosts on each of 2 million networks. Class C addresses start with 110 and are commonly used by small companies.

• Class D – Reserved for multicast group addresses.

• Class E – Reserved for experimental purposes.

Understanding these traditional IP address classes can help identify the size of a network from its IP address range. However, classful networking has mostly given way to classless networking using subnet masks.

What Your IP Address Reveals About You

When you connect to any website, streaming service, game server or other internet endpoint, you automatically share your public IP address to enable two-way communication.

Unfortunately, your IP address can reveal more personal information than you may feel comfortable with. While not as precise as a home mailing address, experienced observers can still glean certain details from your IP:

• Approximate location – Geolocation tools use IP mapping databases to estimate the city, state, or region an IP address is located in. However, these tools are imprecise – IPs only reveal approximate areas, not street addresses.

• Internet service provider – Ownership of public IP address blocks is public record. Looking up the owner of an IP range reveals the associated ISP or company.

• Browsing history – Websites and sophisticated ad networks can track and link your IP address to build profiles of your interests and activity across sites over time.

• Usage habits – Services can profile when you‘re typically online, sites you frequently visit, connection speed, and other behavioral patterns linked to your IP.

No single piece of information may compromise your security outright. However, combined together, your IP address can allow observers to paint an alarmingly detailed picture of your digital life and habits. It‘s essential to take steps to protect your privacy.

All About Cookies: What They Are and How They Work

Along with your IP address, websites use small data files called cookies to identify your device and track online activity. But what exactly are cookies, and how do they work?

The Basics: What Are Cookies?

Cookies are tiny text files, ranging from a few hundred bytes to a few kilobytes, that websites store in your device‘s web browser. They contain data that allows sites to identify your browser and device specifically, and store information that can be retrieved later.

The first time you visit a site, it sends a cookie containing a unique, random identification string to your browser. Your browser accepts and stores the cookie. When you return to that site, your browser automatically sends the cookie back, allowing the site to recognize you as a returning visitor rather than a new user.

This is what allows you to stay logged into sites, maintain items in your shopping cart across visits, save website preferences, and have a personalized experience.

Cookies were invented in 1994 by programmer Lou Montulli to solve the problem of websites being unable to distinguish between new and returning visitors. They paved the way for key innovations like shopping carts, user sessions, and personalized site experiences.

How Do Cookies Work? A Simple Step-By-Step Example

Here‘s a straightforward example walkthrough of how cookies function:

1. You visit ExampleShop.com for the first time.

2. ExampleShop‘s server sends your browser a cookie containing a unique, randomly generated string like "8x7v5f9a" and stores this ID in its user database.

3. Your browser accepts the cookie, saves the file locally, and returns a copy of it to ExampleShop on your next request.

4. When you visit ExampleShop again later, your browser automatically attaches the cookie value to the request.

5. ExampleShop recognizes the "8x7v5f9a" ID in the incoming cookie and can identify you as a returning visitor.

This allows ExampleShop to remember you as you browse across product pages, add or remove items from your cart during the session, save delivery preferences, and have a personalized experience across visits.

The Controversy Around Cookies: Tracking and Privacy Issues

The core functionality of cookies brings significant privacy tradeoffs. Companies can leverage cookies to track users in ways they likely never expected or agreed to.

Marketers use cookie tracking to gather data about your web activity habits and build extensive behavioral profiles. They can then target personalized ads to your interests or sell data to brokers.

Your browsing history, purchases, search queries and more can be tied back to your cookie ID and aggregated into a detailed profile about your personal life.

Sophisticated tracking networks share cookie data for cross-site profiling. You may be followed across the web by cookies from platforms you don‘t even have accounts on.

According to a Princeton study, cookies from online advertisers and data brokers are present on over 80% of websites. Over 90% of pages contain third-party tracking resources like cookies or browser fingerprinting scripts.

This "surveillance marketing" ecosystem has led to growing scrutiny of cookie tracking and demands for better privacy protections.

How to Manage, Delete, or Block Cookies in Your Browser

If you wish to take control of your privacy online, managing or periodically clearing out cookies is a good place to start. Here are tips for the most popular web browsers:

Chrome

• Click the 3 vertical dots > Settings > Privacy and Security
• Select Cookies and other site data > See all cookies and data
• Search to delete specific sites or click Clear all cookies

Firefox

• Click the 3 horizontal lines > Settings > Privacy & Security
• Go to Cookies and Site Data and search/delete individual cookies
• Alternatively, click Clear All Cookies

Safari

• Click Safari > Preferences > Privacy
• Choose Manage Website Data > Search and delete specific cookies
• Or, click Remove All to clear everything

Internet Explorer

• Open the Tools menu (gear icon) > Internet Options > General tab
• Under Browsing History, select Delete… and check Cookies
• Click Delete to confirm

All Browsers

• Enable "Do Not Track" signal in settings to opt-out of tracking cookies
• Use private/incognito modes and don‘t sign into accounts to avoid being tracked
• Install browser extensions that automatically clear cookies after each session

DNS and How It Relates to IP Addresses

The Domain Name System (DNS) plays a crucial role in mapping human-readable domain names to numerical IP addresses.

Here‘s how it works:

When you type a web address like exampleshop.com into your browser, your computer sends a DNS lookup request to your internet service provider‘s DNS servers. These servers maintain databases matching domain names to IPs.

The DNS server looks up the IP address tied to exampleshop.com, then returns the IP to your computer. Your browser can then use this IP to connect and load the website.

Without DNS converting domains to IPs in the background, you‘d have to memorize and type websites‘ numerical addresses.

DNS servers can observe your traffic and logging DNS lookups reveals all the sites you visit. Using a private DNS provider like Cloudflare (1.1.1.1) or encrypting DNS queries can prevent this.

Protecting Your Online Identity and Data with VPNs and Proxies

There are several methods power users can leverage to protect their IP address, evade cookie tracking, and maintain their privacy across the web:

Use a Trusted VPN Service

A VPN, or virtual private network, encrypts your internet traffic and routes it through a private server run by the VPN provider. This masks your IP address so trackers see the VPN server‘s IP instead of your actual one. VPNs also prevent ISPs from monitoring your browsing activity.

Leading VPNs like ExpressVPN, NordVPN, and Surfshark make it easy to protect your IPs and cookies on all your devices. Enable them whenever you access public Wi-Fi or want to browse without being tracked.

Leverage Anonymizing Proxy Servers

Proxies act as intermediaries between you and the wider internet. Your traffic flows through the proxy server, hiding your IP address from the sites you access. Public proxies are available, but can be slow and unreliable.

Use Tor Browser

Tor Browser directs your traffic through its own overlay network of global relays run by volunteers. This makes it extremely difficult to monitor or record both your IP and your browsing activity. The tradeoff is slower speeds.

Regularly Clear Cookies and Site Data

As outlined above in the browser tips, periodically wiping your cookies removes data trackers have saved about your browsing habits and resets your digital footprint.

The Ongoing Balancing Act Between Convenience and Privacy

IP addresses and cookies allow you to conveniently access internet content, services and apps you love. But with this comes significant privacy tradeoffs.

Your IP address and cookies enable both first-party services and third-party trackers to monitor your online activities, interests and habits – often without your knowledge or consent.

This has led to escalating scrutiny of the "surveillance marketing" ecosystem from consumers, regulators, lawmakers and privacy advocates. But easy web functionality relies on technologies like IPs and cookies under the hood.

There are no perfect solutions, but being an informed and empowered internet citizen means understanding the privacy risks associated with core mechanisms like IP addresses and cookies.

Taking proactive steps – like using a VPN, disabling cookies, leveraging browser protections, opting out of tracking – can help tilt the scales back towards maintaining your privacy as you navigate the modern web.