NAT (Network Address Translation) is a networking process that allows multiple devices on your home network to share a single public IP address provided by your Internet Service Provider (ISP). When you connect devices like phones, laptops, and smart home products to your wifi, NAT translates their private IP addresses to your public IP address so they can communicate with the internet.
What is double NAT?
Double NAT (Network Address Translation) lets you set up your eero network quickly without changing your existing modem or router settings. Double NAT creates two separate networks by having two routers perform NAT. Your Gateway eero connects to your existing router instead of directly to your modem.
How do I set up my network in double NAT mode?
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:
Plug your Gateway eero into the modem/router combo and follow the setup instructions from there. In this case, you have the option of putting your modem/router combo in bridge mode, so it'll only act as a modem.
When using double NAT, 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. See How do I resolve wifi network conflicts?.
Note: For the best performance and to access all eero features, we recommend putting your modem/router combo in bridge mode after initial setup. To learn more about bridge mode, see What is bridge mode?
What are the drawbacks of double NAT?
Double NAT works well for most networks, but there are a few situations where you may notice limitations:
- Network conflicts: If your eero network and your existing router share the same wifi name and password, devices may have trouble choosing which network to connect to. Use a different wifi name and password for your eero network to avoid this.
- Increased latency: Data passes through two routers instead of one, which may add a small delay. You're most likely to notice this during online gaming or video calls.
- Gaming issues: Game consoles like Xbox may show a "Strict" or "Moderate" NAT type, which can make it harder to join online games or voice chat. The extra NAT layer can limit your console's ability to connect directly with other players.
- VPN issues: Some VPNs may have trouble establishing a secure tunnel through two layers of NAT. If this happens, you may notice occasional disconnections or difficulty connecting.
- VoIP issues: Internet-based phone services may occasionally experience dropped calls, one-way audio, or difficulty connecting. VoIP relies on direct connections that two layers of NAT can sometimes interfere with.
- DDNS issues: Dynamic DNS services may not work as expected with double NAT. Your eero's public-facing IP is a private IP from your first router, not your ISP-assigned public IP, which can prevent DDNS-based remote access from reaching your network.
- Port forwarding and UPnP conflicts: Port forwarding and UPnP may need extra configuration with double NAT. Since both routers manage traffic independently, you may need to open ports on both your eero and your existing router.
- Slower speeds: Most networks perform well with double NAT. If you notice slower speeds, double NAT is worth checking as a possible factor.