Computer networking in 5 minutes: Static IP vs dynamic IP

What is an IP address?#

An Internet Protocol address, or IP address, is a unique identifier assigned to every device on a TCP/IP network. The Internet Protocol is the set of rules that outlines how data should be transported across the internet or local networks. IP addresses help identify devices and allow them to communicate with each other.

Internally, IP addresses are stored as numbers. The Domain Name System (DNS) allows us to use words to identify different servers on the internet, such as an application, server, or website. When we type a URL into our search bar, DNS looks up that domain’s IP address and returns it to our network device. There are two main versions of IP addresses: IPv4 and IPv6.

IP addresses are strings of four numbers separated by characters. For example, an IP address could look like this: 152.132.4.23. They’re produced by a division of the Internet Corporation for Assigned Names and Numbers to help make the internet more secure and accessible.

We can think of IP addresses as physical home addresses. We can exchange addresses with friends and family. Those addresses give us a destination that allows us to communicate with friends and family through different communication methods like birthday cards, letters, and more.

How does an IP address work?#

All devices communicate with one another using the Internet Protocol (IP). Here’s how it works:

Before our devices connect to the internet, they connect to a network that’s connected to the internet. This network gives us access to the internet. For example, the network that we use at home will most likely be our Internet Service Provider (ISP). After this, our ISP will assign an IP address to our device. Our internet activity will go through the ISP and then be routed back to us using our assigned IP address.

If we leave our home and take our personal device with us, our IP address from our home network doesn’t come with us. Let’s say we go to a hotel. When we want to use the internet at the hotel, we’d probably connect to their Wi-Fi network. Since we’re using a new network, we’re temporarily assigned a new IP address. This temporary IP address is assigned to us by the hotel’s ISP.

Can our IP addresses change? Yes, they can! If we turn our modem or router off, our IP address may change. We can also contact our ISP to change our IP address. This is one of the reasons why DNS is so important. Instead of directly informing others when our IP address changes, we can directly inform our DNS server. This means that any other device that contacts the DNS server will get the updated information for the new IP address.

Static IP addresses#

A static IP address is an IP address that doesn’t change. Our static IP addresses usually stay the same unless our network architecture changes or our devices are out of commission. Static IP addresses are typically used for servers or other important networking equipment. They’re popular within business settings because they ensure that the devices connected to them keep a consistent address. They also work well for remote access solutions.

A static IP address is assigned to a device by an ISP. Typically, static IP addresses add to the cost of your internet service.

Dynamic IP addresses#

A dynamic IP address is an IP address that can regularly change. An ISP will buy a large number of dynamic IP addresses and assign them to their customer’s devices. Dynamic IP addresses are often reassigned. Reassigning IP addresses helps internet providers save money and ensure a higher level of security. It also means that they don’t need to take the time to reestablish any network connections if we go on a vacation or move to a new location.

Dynamic IP addresses are more common for consumer equipment and personal use. A dynamic IP address is assigned to a device by our ISP’s Dynamic Host Configuration Protocol (DHCP) servers. The DHCP server typically uses network routers to assign addresses to devices.

Static IP vs dynamic IP#

There’s not always a clear answer when it comes to deciding between a static or a dynamic IP address. When choosing between the two, it’s important to consider your connection environment. In other words, static IP addresses tend to be better for businesses, while dynamic IP addresses tend to be better for personal or home networks.

Let’s take a look at some of the pros and cons of static and dynamic IP addresses:

Static IP addresses#

Dynamic IP addresses#

Wrapping up and next steps#

Today, we took a closer look at IP addresses and discussed what they are and how they work. IP addresses are an important part of computing networking because they allow our devices to properly communicate with other devices. Static and dynamic IP addresses are the two types of IP addresses with different purposes. It’s often said that static IP addresses are better for businesses, and dynamic IP addresses are better for personal use.

We covered a lot today, but there’s still so much more to learn! Some recommended topics to cover next include:

• DNS servers
• Network addresses
• Firewalls
• Routing in IP

To get started learning these concepts and a lot more, check out Educative’s course Grokking Computer Networking for Software Engineers. This hands-on course will teach you the fundamentals of networks, socket programming in Python, command-line tools, and much more. By the end, you’ll have a deeper understanding of computer networking essentials.

Happy learning!

Continue reading about networking#

• What is the OSI model? 7 layers explained in detail
• Computer networking 101: Terms, tools, and getting started
• Behind the scenes: What happens when you type a URL in a browser