Authored by: Support.com Tech Pro Team
How to setup eero on an existing router
To get the most out of your eero WiFi system, we recommend having your eero WiFi system replace your current router and having your gateway eero plugged directly into your modem. However, if you'd like to keep using your existing router, you absolutely can.
In this scenario, you will have two options for using your eeros: putting them in bridge mode or double NAT-ing them.
While it sounds a bit complicated, double NAT-ing your eeros is fairly simple.
If you have a separate router and modem, don't plug your gateway eero directly into your modem, as the eero app suggests. Instead, plug your gateway eero into your existing router. From there, follow the remaining setup instructions in your eero app.
If you have a modem/router combo device, simply plug your gateway eero into the combo device and follow the setup instructions from there. In this case, you also have the option of putting your modem/router combo device into bridge mode, so it'll only act as a modem. For more, see this article.
When double NAT-ing, be sure to use a different SSID and password for your eero network than your existing network. Running two networks with the same SSID simultaneously will lead to technical complications.
If you have any other questions, please don't hesitate to reach out to our team. We are more than happy to help answer or address any concerns.