How to Obtain a Fixed IP Address

Sometimes your computer's IP address may change when it connects to a network, even though you made no modifications to your setup. It happens frequently if you keep 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 devices remotely over the internet.

Using Fixed IP Addresses on Home Networks

Your home network router (or another 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 is re-assigned to the next device that connects to it.

Routers typically set a relatively short DHCP lease time, which is about 24 hours, and also allow administrators to change the default value. Shorter leases make sense on large networks with many devices connecting and disconnecting, but generally, they are not helpful on home networks. By changing your DHCP lease time to a longer value, you increase the likelihood that each computer keeps 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 computer always uses 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 in to 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.

IP addresses for mobile devices connecting to public Wi-Fi hotspots also 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 VPNsolutions—especially configurations you create using technologies like Algo—route all your traffic through a defined IP address. This capability can be useful when a source or destination IP address must be on an approved list. 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.