What is an IP address (Internet Protocol address)?
An Internet Protocol (IP) address is a unique numerical identifier for every device or network that connects to the internet. Typically assigned by an internet service provider (ISP), online devices use an IP address to communicate across the internet.
Each IP address can send information to other IP addresses through discrete chunks known as packets. Each network packet contains the data being transferred along with a header containing the packet's metadata.
How to locate an IP address
There are many ways to look up the IP address of a device. The simplest is to type "what is my IP address?" into an available internet browser. The returning address will be the public IP address of the requesting device. For other specific devices, try the following methods:
Windows 10 and Windows 11
- Select Start > Settings > Network & internet > Wi-Fi and the Wi-Fi network being used.
- Under Properties, look for the device IP address listed next to IPv4 address.
- Alternatively, you can access the Command Prompt, type in "ipconfig/all" and scroll down to where the IPv4 address is provided.
Mac
- Go to System Preferences.
- Select network. This should show the IP address information.
iPhone
- Go to Settings.
- Select Wi-Fi and click on the information icon, which is the blue I in a circle to the right of the connected network.
- The IP address should be visible under the Dynamic Host Configuration Protocol (DHCP) tab.
Various websites, such as whatismyipaddress.com, also automatically find the IP address of a device.
Comparing the two IP versions
Two versions of IP addresses are commonly used on the internet: IPv4 and IPv6. An IPv4 address is expressed as a set of four dotted decimal numbers, where each octet is separated by a period, such as 192.168.35.4. The three digits in the first octet represent a particular network on the internet, while the rest of the digits represent the actual host address within the local network, such as a workstation or a server.
By comparison, an IPv6 address is comprised of eight groups of four hexadecimal digits separated by colons, such as 2620:cc:8000:1c82:544c:cc2e:f2fa:5a9b.
Other differences between IPv4 and IPv6 include:
- IPv4 is 32-bit, whereas IPv6 is 128-bit.
- In IPv4, binary bits are separated by a dot (.); IPv6 separates binary bits by a colon (:).
- IPv4 follows the numeric addressing method and IPv6 is alphanumeric.
- IPv4 offers 12 header fields and IPv6 offers eight header fields.
- IPv4 has checksum fields and IPv6 does not.
- IPv4 supports broadcast address, which is a type of special address that transmits data packets to every node on the network. IPv6 does not support broadcast, but instead uses a multicast address, which is a logical identifier for a collection of hosts on a network.
- IPv4 supports Variable Length Subnet Mask, but IPv6 does not.
- When mapping to media access control (MAC) addresses, IPv4 uses the Address Resolution Protocol (ARP). IPv6 uses the Neighbor Discovery Protocol (NDP), which uses stateless auto-configuration and address resolution.
How do IP addresses work?
An IP address is part of the TCP/IP suite of protocols. It works behind the scenes, helping devices and websites connect with each other on the internet.
Every time a computer makes a request to access a website, the requesting computer must know where the website resides and how to reach it. This is where the IP address comes into play. The requesting computer connects to the network router, which connects to the server where the website lives. The web server then pulls the website information and sends it back to the requesting computer. Each device in this process -- including the computer, router and web server -- carries a uniquely identifiable IP address, without which the transfer of information cannot take place.
Types of IP addresses
Here is a list of the most common types of IP addresses:
1. Private IP addresses
Each device connected to a home network or a private network carries a private IP address. Private IP addresses are non-internet facing and are only used on an internal network. Devices with private IP addresses might include computers, tablets, smartphones, Bluetooth devices, smart TVs and printers, as well as internet of things (IoT) products
2. Public IP addresses
An ISP assigns public IP addresses, which enable a router to communicate with the internet or an outside network. Public IP addresses cover the entire network, meaning multiple devices sharing the same internet connection will also share the same public IP address.
3. Dynamic IP addresses
Dynamic IP addresses are constantly changing, meaning a new dynamic IP address is assigned to a device every time it connects to the internet. ISPs buy large pools of IP addresses to assign to their customers automatically. They revolve and reuse these addresses between different customers to generate cost savings and provide easier network management. A dynamic IP address also offers security benefits, as it is harder for cybercriminals to hack into a network interface if its IP is constantly changing.
4. Static IP addresses
Unlike dynamic IP addresses, static IP addresses never change once they're assigned by the network. While most internet users and businesses do not require static IP addresses, they are a requirement for businesses that wish to host their own web servers. A static IP address ensures that all websites and email addresses associated with a certain web server will always have a consistent IP address so it can be reached on the internet.
These are IP addresses for website owners who do not host their websites on their own servers but rather rely on a hosting company to do so. There are two subtypes of website IP addresses:
- Shared. Mostly used by small businesses that rely on a managed hosting service, a shared IP address is shared among many different websites.
- Dedicated. A dedicated IP address is a unique IP address assigned to an individual website. Dedicated IP addresses help website owners avoid getting blocked or blocklisted, something that owners of shared IP addresses might face when malicious behavior is exhibited by other websites sharing the same IP.
IP address security
Cybercriminals can exploit an IP address in several ways, and once an IP address is exposed, it can be used for various malicious purposes. Hiding IP addresses and accessing the internet securely through a virtual private network (VPN) service can help keep the address private and secure. Another method would be to mask the IP address by using a proxy server or a browser that anonymizes web traffic.
Cybercriminals exploit stolen IP addresses in some of the following ways:
- Downloading illegal content. Cybercriminals often use stolen and unprotected IP addresses to access and download illegal content such as viruses and ransomware. This way, they can avoid being tracked, as the IP addresses get traced back to the IP address owners.
- Location tracking. Most public addresses can be used to narrow down someone's physical location, such as their city of residence. With some digging, criminals can even locate the actual home address of an IP address owner.
- Distributed denial-of-service attacks. By obtaining an IP address, criminals can carry out targeted DDoS attacks against a network. During these attacks, cybercriminals send massive amounts of fake traffic to a website to crash it.
- Sending spam. Advertisers can embed tracking programs in online activities and articles that can record IP addresses. They can then use the recorded IP addresses to generate spam and to target advertising based on a visitor's browsing history.
- Stealing identities. Identity theft and ransomware attacks are on the rise, and cybercriminals are always on the lookout for personally identifiable information (PII) such as social security numbers or mailing addresses. While an IP address isn't technically PII, it can help a cybercriminal gain access to other information. For example, if cybercriminals obtain a person's IP address, they can easily track down their ISP and attempt to impersonate them through vishing attacks that can cause the ISP to divulge personal data.
How will artificial intelligence impact IP addresses?
AI, which is rapidly impacting just about everything in IT, can potentially affect IP addresses in a few key ways:
- IP address management. By optimizing the allocation and management of IP addresses, support for advanced technologies such as IoT can be enhanced through better prediction of usage activities, identification of inefficient usage, dynamic allocation of IP addresses and improved resource utilization
- Improvements in cybersecurity. AI can identify and analyze suspicious IP traffic so that potential attacks can be identified and mitigated faster.
- Network performance improvements. Certain network traffic performance metrics, such as increased throughput and reduced latency, can be enhanced by using AI to optimize data routing, identify and bypass regions of congestion and deliver better network trouble resolution.
- Network policy automation. Compliance with established network policies, regulations and other controls can be enhanced using AI to perform various compliance activities, such as managing IP ranges for proper usage or geographic considerations.
- Acceleration of IPv6 usage. By taking advantage of the enormous number of potential IP addresses afforded by IPv6, AI could help streamline the transition from IPv4 to IPv6 addressing.