Fix double NAT when two routers run at the same time (2024)

If you have two separate ISP devices, a modem and router, turn off and unplug the ISP-provided router, then connect your modem directly to your Wifi device.

If your ISP-provided router is combined with the ISP's modem in a single device, enable Bridge mode on your modem/router combo to fix the double NAT issue. When you enable Bridge mode on your ISP router, it'll turn off its NAT and allow your Wifi device to be the sole device that performs NAT.

1. Connect a computer directly to your ISP-provided router with an Ethernet cable.
2. Log in to your modem and router combo, then find its settings to enable Bridge mode.
3. To access your router's settings, you might have to open an Internet browser and enter your router's IP address in the address bar like this:

Steps will vary depending on the device. Many ISPs and manufacturers provide instructions on how to enable Bridge mode. To learn how to turn on Bridge mode, check your ISP's support website.

A single Wifi device that isn't part of a mesh system can be set to Bridge mode. Bridge mode disables the DHCP and routing functions so double NAT is no longer an issue. In Bridge mode, this single mesh point will operate as a pure Wi-Fi access point connected over an Ethernet wire to your modem.

Note: Bridge mode on Wifi devices only works on a single Wifi device setup. If you create a mesh network with multiple Wifi devices, your primary Wifi router can't be in Bridge mode because it needs to control settings and communication within your Wi-Fi network. If your primary Wifi router is in Bridge mode, in addition to losing mesh capability, you'll also lose some functionality of your Wifi device such as:

• Family Wi-Fi, priority device and Guest Wi-Fi will be unavailable.
• DNS and WAN settings can't be edited.
• You won't be able to test your mesh connection.

Additionally, Bridge mode disables many of Google Wifi and Google Nest Wifi's security protections. This is because your upstream router (the modem/router combo in the above scenario) is the one performing DNS steering, packet inspection, executable patching and so on.

Your Wifi devices automatically install security updates to maximise your privacy and security. These protective features are most effective, and in some cases, only effective, when all traffic passes through your primary Wifi router, instead of through another router.

If you have a third-party router, you can wire your primary Wifi router to it, then mesh additional Wifi points downstream.

If you still want to turn your primary Wifi device into a bridge, you can follow the steps below:

Your Internet Service Provider (ISP) usually assigns your home Internet connection a single public and globally unique IP address. You can view Wifi device information in the Google Home app.

Most households have multiple devices connected to its home network, with each device requiring their own IP address. Your router assigns a local IP address to each device in your home network through DHCP (Dynamic Host Configuration Protocol).

Google Nest Wifi Pro, Nest Wifi and Google Wifi devices transfer data that comes in or goes out from the public IP address to the device in your home network. This process of transferring data from the public IP address to the specific device local IP address is called Network Address Translation (NAT).

Internet providers usually provide a modem or gateway, which is a modem and router combo, that converts the signal that comes into your home Internet connection. In many cases, the modem or gateway is set up to perform NAT. A double NAT happens if another router, for example a Nest Wifi router, is connected to the ISP modem or gateway. All this means is that data is going through a NAT process twice, which might cause a very small delay, of the order of milliseconds, to data getting in and out of your home.

You can connect two or more independent (non-meshed) router systems to extend the Wi-Fi coverage in your home. But when you have two routers, each with their own private Wi-Fi network, your personal devices can have a hard time communicating with each other because of the different sets of IP addresses and firewalls between the two independent router systems.

For example, let's say you want to wirelessly print a picture from your computer. If you have two independent networks, it's possible your computer is on one network while your printer is on the other. And if both networks are private, your computer won't be able to tell your printer to print the picture.

Double NAT

A double NAT can also result in performance issues if you play online games or use port forwarding rules and UPnP.

To fix this, Bridge mode lets multiple routers share one single Wi-Fi network. Here's what that could look like:

Bridge mode