How to Obtain a Fixed IP Address

Sometimes your computer's IP address may change when it connects to a network, even though you have made no modifications to your setup. It happens more frequently if you have kept the computer shut off or if you have been away from home for a while. This is an expected behavior of Dynamic Host Configuration Protocol (DHCP), which most networks use. However, some people require fixed IP addresses to access their device remotely over the internet.

Using Fixed IP Addresses on Home Networks

Your home network router (or other DHCP server) keeps track of how long ago it issued your computers IP addresses. To make sure that the network does not run out of IP addresses, DHCP servers set a time limit called a lease for how long each computer can be guaranteed to keep their same address, after which the address will be re-assigned to the next device that tries to connect to it. Routers typically set a relatively short DHCP lease time, which is about 24 hours and also allows administrators to change the default value. Shorter leases make sense on large networks with many devices connecting and disconnecting but generally aren't helpful on home networks. By changing your DHCP lease time to a longer value, you can increase the likelihood that each computer will keep its lease indefinitely.

Alternatively, with more effort, you can set up static IP addresses on a home network instead of using DHCP. Static addressing guarantees your computers will always use the same fixed IP address no matter how long it's disconnected between sessions.

To change DHCP lease times or change your network to static addressing log into your home router as an administrator and update the appropriate configuration settings.

Using Fixed IP Addresses on Public Networks

While you can control the addresses assigned to your home computers, the IP addresses assigned to your router by your internet provider are still subject to change at the provider's discretion. To obtain a static IP address from an internet provider requires signing up for a special service plan and paying extra fees.

Mobile devices connecting to public Wi-Fi hotspots also will have their IP addresses change regularly. It is not possible to keep the same public IP address for a device when you move between public networks.

Use a Virtual Private Network

Some VPN solutions—especially configurations you create yourself using technologies like Algo—will route all your traffic through a defined IP address. This capability can be useful for use cases where a source or destination IP address must be white-listed. For example, some security products require that a dedicated or specifically identified IP address or IP range access it. Using a VPN even if your ISP won't supply a fixed public IP address can help you surmount this barrier.