DHCP Reservation vs. Static IP: Which Should You Use?

For almost every device on a home network, use a DHCP reservation: you set it once in your router, and the router gives that device the same IP address every time it connects. Set a static IP on the device itself only when the device can’t get a reservation, for example because you can’t change your router’s settings, and when you do, choose an address outside the range your router hands out automatically. That one rule avoids the most common cause of address conflicts: two devices ending up with the same address.

What each one is

Your router runs a DHCP server, the service that gives every phone, laptop and smart plug an IP address when it joins the network. Most of those addresses are temporary leases, which is why a device’s address can change after a restart.

A DHCP reservation tells the router: whenever this specific device asks, give it this specific address. Google’s definition: “your Wi-Fi network assigns the same IP address to a specific device whenever that device connects to your network.” The router recognizes the device by its MAC (hardware) address: NETGEAR’s and TP-Link’s reservation screens both ask for it. The DHCP standard itself, RFC 2131, describes this as manual allocation, where “a client’s IP address is assigned by the network administrator, and DHCP is used simply to convey the assigned address to the client.”

A static IP is set in the device’s own network settings instead of the router. The device stops asking the router for an address and uses the one you typed in, along with a subnet mask, gateway (your router’s address) and DNS servers. Apple’s Mac help puts it simply: “If your ISP or administrator gave you an IP address, choose Manually, then enter the address in the IP address field.”

One source of confusion: router makers often call a reservation a “static IP” in their apps. Google’s help page, for instance, walks you through choosing a device and entering “a static IP address” while making a reservation. In this guide, “static IP” means the address is configured on the device.

Side by side

Why a reservation is the safer default

The router keeps the whole address list in one place. When it reserves an address for your printer, it knows not to give that address to anything else, and every reservation can be seen and changed from one screen.

A static IP set on a device is invisible to the router’s DHCP server. If you pick an address inside the pool the router hands out, the router may later give the same address to a phone or TV. EnGenius explains it in its support FAQ: “If you assign a local static IP that is in the DHCP lease pool, the DHCP service will not know it.” Its advice is to assign static addresses “outside the DHCP lease pool.”

RFC 2131 does tell DHCP servers that they “SHOULD check that the offered network address is not already in use,” for example with a ping, and tells devices to check a new address too. That’s a safety net, not a guarantee, and a device that’s switched off when the check runs won’t answer it. On Windows, Microsoft lists the result when you do collide: “The static IP address that was just configured is already in use on the network. Please reconfigure a different IP address.”

When a static IP still makes sense

• You can’t change the router’s settings, for example on some ISP-managed or building-provided networks. A static IP outside the pool, if you know the pool, is the workaround.
• The device must work even if DHCP doesn’t, such as a network switch, access point or home server that other devices depend on. Static addressing is a common choice for network infrastructure; an EnGenius support FAQ starts from the premise that “static IP addressing is recommended in most access point deployments.”
• The device rotates its MAC address and you can’t turn that off, since a reservation keyed to the old MAC address won’t match.

For printers, cameras, game consoles, NAS boxes and smart-home hubs on a typical home network, a reservation does the job with less risk.

Brand rules that trip people up

Router makers don’t all handle reservations the same way. Check these before you pick an address:

• ASUS says the reserved address “needs to be in the IP pool of your DHCP server,” and that the DHCP Server page shows the maximum number of manual assignments (it gives 128 as an example). Its menu path is Advanced Settings > LAN > DHCP Server.
• TP-Link says the reserved IP “must be on the same subnet with the LAN IP.” In TP-Link’s example, with a LAN address of 192.168.0.1, that means 192.168.0.2 to 192.168.0.254. The setting is under Advanced > Network > DHCP Server > Address Reservation, and TP-Link’s steps end with a router reboot.
• NETGEAR puts it under ADVANCED > Setup > LAN Setup (or Settings > Setup > LAN Setup on some models), in the Address Reservation section. The device picks up its new address the next time it contacts the router; NETGEAR says to “reboot the computer, or access its IP configuration to force a DHCP release and renew.”
• Google routers managed in the Google Home app handle it under Wifi > Network settings > Advanced Networking > DHCP IP reservations. Google says, “You may need to disconnect this device from your Wi-Fi network and reconnect it before it is assigned the reserved IP.”
• eero lists reservations under Reservations & Port Forwarding in the eero app, but not in bridge mode: eero lists “IP reservations and port forwarding” among the features you lose there.

That last point applies to any brand. If your router or mesh system is in bridge or access point mode, the device actually running DHCP is your ISP’s gateway or another router, so make the reservation there. Our guide to bridge mode and double NAT explains how to tell which device is in charge.

Watch out for private Wi-Fi addresses

A reservation matches a device by its MAC address. Many phones, tablets and laptops use a private, randomized MAC address instead (Android 10 and later do so by default, according to Google), and eero lists IP reservations among the router features that MAC randomization can affect. If the address changes, the reservation stops matching. For a phone you want to reserve an address for, use a fixed private address or turn the feature off for your home network only. Our private Wi-Fi address guide covers the settings on iPhone, Android and Windows.

How to set a static IP if you need one

First, find your router’s DHCP pool in its LAN or DHCP settings, and choose an address in the same subnet but outside that range. Then:

Windows (Control Panel): open the network connection’s Properties, select the Internet Protocol (TCP/IP) entry for IPv4, click Properties, choose Use the following IP address, and fill in the IP address, subnet mask, default gateway and DNS servers. Microsoft’s instruction is that the address “must be a unique address in the range of addresses that are available for your network.”

Mac: open System Settings > Network, click your connection, click Details, click TCP/IP, then set Configure IPv4 to Manually and enter the address, subnet mask and router.

Write the address down, along with the pool range. If you later change routers or the router’s subnet, a device with a static IP won’t follow along on its own.

Where this matters next

Most people set up a reservation because something else depends on a stable address, usually port forwarding for a game console, camera or server. Our port forwarding guide picks up from here. If your new address never seems to stick, check the list of connected devices to confirm the device is appearing under the MAC address you reserved.

Sources and verification