Double NAT is the most searched eero 6+ problem, and the fix is a decision about which device does the routing. If your ISP gives you a modem and router in one box, and the eero is plugged into it, two devices are both routing, and the eero app reports a double NAT. It matters for VPNs, some voice and video calling and gaming, not for browsing. The eero community recommends one of two arrangements.
The preferred one is to put the ISP's box in bridge mode, so the eero is the only router. If the ISP's box cannot do bridge mode, you keep its routing and set the eero to bridge: in the app, Settings, Advanced, DHCP and NAT, and choose Bridge, which works but costs you some eero features such as the full network controls. The best layout in the threads is a stand-alone modem feeding the eero gateway.
Differential
Likely causes of “eero 6+ shows double NAT or strict NAT”, and how to tell them apart
- 1
An ISP modem-router combo still routing
What separates it The eero app reports a double NAT
How to confirm Ask the ISP to put its box in bridge mode, or switch the box's routing off
- 2
The eero in automatic mode behind a router
What separates it The app cannot tell it is behind another router
How to confirm Settings, Advanced, DHCP and NAT: choose Bridge if the ISP's box must keep routing
- 3
An ISP box that cannot bridge
What separates it Bridge mode is not offered
How to confirm Keep its routing and run the eero in bridge mode, or ask for a modem-only unit
- 4
A leftover second router
What separates it An old router is still in the chain
How to confirm Remove it or put it in access point mode
- 5
VPN or game traffic failing
What separates it Voice or game connections fail while browsing works
How to confirm Use bridge mode or forward ports on the router that does the routing
Before you touch a setting
Record this first — changing settings destroys the evidence
- The ISP, the modem or gateway model and whether it has a bridge mode
- What the eero app says about NAT
- Which services fail: VPN, calls, games
- The wiring: modem to eero gateway
Try in this order
0 of 6 completedConfirm the arrangement
ReversibleModem and router in one box, then the eero plugged into it, is the double NAT.
Prefer bridge mode on the ISP's box
ReversibleAsk the ISP, or use their app or admin page, to switch the box to bridge so the eero routes.
Or switch the eero to bridge
ReversibleOpen the eero app, Settings, Advanced, DHCP and NAT, choose Bridge and save.
Restart in order
ReversibleModem or ISP box first, then the eero gateway, then the nodes.
Test a service that failed
ReversibleTry the VPN, call or game that was blocked.
Consider a modem-only unit
ReversibleA stand-alone modem feeding the eero is the cleanest setup.
Model-specific
What is true of this model and not of its siblings
- The cleanest layout
- Stand-alone modem, then the eero gateway, then a switch or nodes.
- Why the app warns
- The eero detects a private address on its WAN port, which means another router sits in front of it.
Stop boundary
When this stops being a self-service repair
- !If the ISP will not bridge its box, ask whether a modem-only unit is available
- !If the eero shows no internet after a change, restore the ISP's box settings
- !If you rely on the ISP's phone or TV service, ask before changing modes
Evidence ledger
Sources behind this answer
Exact questions
Common questions
What is double NAT on an eero 6+?+
Two routers, the ISP's box and the eero, both routing, which breaks some VPNs, calls and games.
Should I bridge the ISP box or the eero?+
Bridge the ISP box if it allows it, so the eero is the only router; otherwise bridge the eero.
What do I lose in eero bridge mode?+
Some of the eero's network features, since the other router does the routing.
Does double NAT slow my internet?+
Not browsing speed; it affects specific services.