When to Use a Static IP Address

A static IP address, or fixed IP address, is an IP address that never changes. Not everyone needs a static IP address, but knowing how they differ from dynamic IP addresses can help you understand whether you should use a static IP address.

Here are some example situations for when you might need a static IP address:

• Setting up a home file server
• Adding a second router to a network
• Enabling access to a computer when away from home/work
• Forwarding ports to certain devices
• Sharing a printer over a network
• Connecting to an IP camera when away from home

The terms were mentioned only briefly above, and that's because they're pretty simple to understand. At the core, the only real change you'll notice between static vs dynamic IP addresses is that the former never changes, while the latter does.

Most people don't really care if their IP address changes. If you never know what your IP address is, and never have a reason to have it stay the same, then dynamic addresses are perfectly fine for you.

However, if your network or computer is set up a specific way where some devices would work easier, and setup made smoother for you as the admin, if an IP address always stayed the same, then static addressing is what you want.

Static IP addresses are assigned manually by an administrator. In other words, the device receiving the static IP is given a very specific address (such as 192.168.1.2), and from then on the address will never change.

In an opposite method, dynamic IP addresses are assigned not manually but automatically, by DHCP (Dynamic Host Configuration Protocol).

Static IP addresses are necessary for devices that need constant access.

For example, they're basically required if your computer is configured as a server, such as an FTP server or web server. This is a good thing, because if you want to ensure that people can always access your computer to download files, then you need to force the computer to use a static, never-changing IP address.

Alternatively, if the server were assigned a dynamic IP address, it would change occasionally which would prevent your router from knowing which computer on the network is the server.

Similarly, if you want to access your home computer while you're on trips, or your work computer when you're at home, setting up the computer to use a static IP address lets you reach that computer all the time without fearing that the address will change and block your access to it.

Consider a shared printer as another example for when to use a static IP address. If you have a printer that everyone in your house or office needs to share, you'd give it an IP address that won't change no matter what. That way, once every computer is set up to connect to that printer, those connections will remain indefinitely because the address will never change.

Here are some other reasons to use static IPs:

• They provide slightly better protection against network security problems than does DHCP address assignment.
• Some network devices don't support DHCP.
• Helps avoid potential IP address conflicts where DHCP might supply an address already assigned elsewhere.
• Provides geolocation that's more accurate than a dynamic IP address.

Because a static IP address is assigned manually, it's much less efficient for a network admin to give them out, especially in mobile situations. They have to often visit the device in person to give it an IP address instead of letting DHCP assign the address automatically.

For example, you wouldn't set a static IP address on a smartphone because the moment it reaches another Wi-Fi network, the address might no be supported on that network, meaning that it won't be able to access the internet.

Dynamic addressing would be much more convenient in this situation because it's easy for administrators to set up. DHCP works automatically with minimal intervention needed, allowing mobile devices to seamlessly move between different networks.

Businesses are more likely to use static IP addresses than home networks. Implementing static IP addresses isn't easy and frequently requires a knowledgeable technician.

However, you can have a static IP address for your home network. When making static IP assignments for local devices on home and other private networks, the address numbers should be chosen from the private IP address ranges defined by the Internet Protocol standard:

• 10.0.0.0–10.255.255.255
• 172.16.0.0–172.31.255.255
• 192.168.0.0–192.168.255.255

These ranges support many thousands of different IP addresses. It's common for people to assume that any number in the range can be chosen and that the specific choice doesn't matter much. This is untrue.

To choose and set specific static IP addresses suitable for your network, follow these guidelines.

• Do not choose any addresses that end with .0 or .255. These addresses are usually reserved for use by network protocols.
• Do not choose the addresses at the beginning of a private range. Addresses like 10.0.0.1, 192.168.0.1, and 192.168.0.100 are commonly used by network routers and other consumer devices. These are the first addresses hackers attack when trying to break into a private computer network.
• Don't choose an IP address that falls outside the range of your local network. For example, to support all addresses in the 10.x.x.x private range, the subnet mask on all devices must be set to 255.0.0.0. If they aren't, some static IP addresses in this range don't work.

Internet service providers (ISP) traditionally assign all their IP address to customers dynamically. This is due to historical shortages of available IP numbers.

Contact your service provider if you prefer a static IP address; you can't get yourself a public IP address that's static without requesting it from your ISP. Customers can sometimes obtain a static IP by subscribing to a special service plan and paying extra fees.