Static Vs. dynamic IP addresses

One issue you might run into when setting up computer networks is IP addresses. The topic of static vs. dynamic IPs can be confusing. What's the difference? When does it matter? Is static better than dynamic?

Static vs. dynamic IPs

Computers use IP addresses to communicate with each other. These are sets of numbers (or, in the case of IP v6, letters and numbers) that act a bit like phone numbers for computer networks. Each part of the IP address narrows down the location of the computer that it refers to.

These addresses aren't particularly easy for humans to remember, so we convert IPs to human-readable names using DNS.

What is a static IP address?

In the world of computers, static IP addresses are ones that never change, whereas dynamic IP addresses are loaned to computers for a short period of time. When the lease period is up, the computer has to ask for a new IP address and could be given a different one than what they previously had.

Static IPs are useful for servers. It would be impractical if the IP address of the server hosting your website changed every few days because you'd need to update the DNS so the domain name pointed to the right IP. Otherwise, your customers wouldn't be able to find it. That's why important services usually run on static IPs.

When are dynamic IPs useful?

The benefits of static IPs are clear. You may be wondering why we bother with dynamic IPs at all, given the convenience of having a fixed address for every device.

The answer is a part of computer history. There are 4,294,967,296 IP v4 addresses in total. There will never be any more than that. In fact, many of those IP addresses are reserved for special uses, so the number of addresses available for day-to-day use is slightly lower.

Now, 4,294,967,296 looks like a large number, but every mobile phone, router and other device that connects directly to the internet needs an IP address. When the internet was first created, we didn't have smartphones, so nobody expected having a limit on the number of addresses would be a problem. But now, there simply aren't enough IP v4 addresses to go around.

Internet Service Providers got around the problem of limited IP v4 addresses by using dynamic IPs. You'd "borrowed" an IP address when you needed it, then released it back to the pool for others to use when you went offline. Residential Proxies also rely on dynamic rotating IPs from real ISPs to offer a wide variety of IP addresses for tasks such as bypassing geographical restrictions.

IP v6 was created to solve the limited address problem of IP v4. There are 340 trillion trillion trillion IP v6 addresses, which should be more than enough for every computer in the world.

There are other benefits of dynamic IP addresses, though. Static IPs require some configuration effort from the sysadmin. Networks that are set up to use dynamic IP addresses offer a better user experience since the user simply connects to the network and is given an IP without having to do anything on their end.

Your voice communications use IPs

VoIP uses the internet for voice and video calls. You can run hundreds of phone lines over a single external IP with SIP trunking. With the right tools, your office communications can be easy to use, reducing the burden on your IT team. Call 8x8 today to schedule a demo of our communications solutions.