When you use DHCP IP reservation, you're telling your Wi-Fi network to assign the same IP address to a specific device whenever that device connects to your network.
Why use DHCP IP reservation or Static IP
Most devices use DHCP, which assigns dynamic IP addresses, as a default. But sometimes, you want devices to always have the same IP address.
For example, a wireless printer. When you print something, your computer and printer locate each other using IP addresses. If your printer’s IP address keeps changing, your computer may not always be able to find it. Giving your printer a static IP address ensures that your computer always knows the address of your printer as it won’t change if it’s rebooted or if a DHCP IP lease expires.
Note:
- You'll need DHCP IP reservation (Static IP for your client) if you want to set up port forwarding to that device.
- You can customize the subnet you use under LAN settings (if you prefer to use a different subnet).
- This article applies only to local devices connected to your router (laptop, smartphone, tablet, etc.). They can have static IP addresses that only your router sees. The outside world won’t see these static IP addresses. But your router can also have a static IP address that the rest of the internet sees. Learn about Static IP for your Wifi point’s WAN.
Change your DHCP settings
- Open the Google Home app
.
- Tap Favorites
Wifi
- Tap DHCP IP reservations
.
- Tap the device for which you’d like to assign a static IP.
- Enter a static IP address, then tap Save
.
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Wifi 
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.Note: You may need to disconnect this device from your Wi-Fi network and reconnect it before it is assigned the reserved IP.