If AT&T Fiber Wi-Fi is connected but has no internet, open Smart Home Manager, check gateway status and outage messages, restart the gateway, then test the AT&T gateway Wi-Fi before troubleshooting your own router or mesh system.
If you use IP Passthrough with your own router, test without that router for one clean baseline. A passthrough or routing issue can make the whole network fail even when the AT&T gateway itself is online.
AT&T Fiber issues can hide behind your router setup
AT&T Fiber connected-but-no-internet problems often happen in homes with more than one network layer. The AT&T gateway may be connected to fiber, then a personal router, mesh system, switch or access points sit behind it. When everything works, this setup feels invisible. When it fails, the Wi-Fi icon can be misleading because the device may be connected to your home network while the gateway, IP Passthrough, DNS route or fiber service is the real break.
Start with the AT&T gateway and Smart Home Manager. If the gateway reports an outage or service problem, your router settings are not the first issue. If the gateway works by itself but your own router fails, then focus on IP Passthrough, WAN address, DNS and routing.
Quick diagnosis table
Try these fixes in order
Prove AT&T service first, then add your extra network gear back one layer at a time.
- 01
Open Smart Home Manager
Check gateway status, outage alerts and device connection details from mobile data if Wi-Fi cannot browse.
- 02
Restart the AT&T gateway
Use the app restart or unplug power, wait, then let the gateway fully reconnect before testing.
- 03
Test the gateway Wi-Fi alone
Connect one phone or laptop directly to the AT&T gateway network to see whether fiber service works before your router.
- 04
Check IP Passthrough
If you use your own router, confirm it receives the expected WAN address and that passthrough is aimed at the right device.
- 05
Return DNS to automatic
DNS changes behind a gateway can create no-internet symptoms even when the connection is alive.
- 06
Check switches and access points
If wired switches or access points are behind your router, test with a simpler layout first.
- 07
Call AT&T for gateway or fiber alerts
Provider-side service, gateway registration or fiber issues need AT&T support rather than local Wi-Fi changes.
Detailed checks
The AT&T gateway is the baseline
Even if you prefer your own router, the AT&T gateway is still the first useful checkpoint. It tells you whether fiber service is present before your network gear complicates the picture.
- Testing gateway Wi-Fi for a few minutes is not giving up on your setup.
- It is how you find where the internet stops.
IP Passthrough can break quietly
IP Passthrough can work well, but it depends on the gateway handing traffic to the right router. If that association changes, your router may lose the path it expects.
- Check the passthrough device, WAN address and reboot order.
- Do not change every firewall setting before checking the basic handoff.
Third-party mesh adds another layer
Eero, Orbi, Deco, ASUS and other routers can sit behind AT&T Fiber, but each adds DHCP, DNS and routing choices.
- When troubleshooting, temporarily remove extra layers.
- If the gateway works alone, reintroduce your router and mesh after each setting is clear.
One-device failures are smaller
If most devices browse but one computer says no internet, the fiber line and gateway are probably fine.
- Check the device IP address, VPN, DNS, security software and saved network profile.
- A single broken laptop should not trigger a gateway reset unless other clues match.
What to record before support
Write down Smart Home Manager status, gateway lights, whether gateway Wi-Fi works, whether your own router receives WAN internet and when the issue started.
- That information helps AT&T support separate fiber service from home-network complexity.
- It also protects you from cycling through the same basic restart steps.
After new fiber install, keep the network simple
A fresh fiber install is not the best time to test every advanced router feature at once. First confirm the AT&T gateway can browse on its own Wi-Fi.
- Then add your router, switch, access points or mesh system back one layer at a time.
- If internet breaks only after your gear returns, the fiber line is less likely to be the main issue.
Gateway address clues matter
Some failures show up as devices trying to send traffic to the gateway instead of your own router. That can happen when routing or passthrough does not match the layout.
- Check the default gateway address on a failing device and compare it with the router that should be in charge.
- This is especially useful in homes with switches and multiple access points.
Mistakes to avoid
Do not assume IP Passthrough is still aimed at the right router.
Do not skip Smart Home Manager status.
Do not reset your mesh before testing gateway Wi-Fi alone.
FAQ
Why is AT&T Fiber Wi-Fi connected but no internet?
Your device may be connected to Wi-Fi while the AT&T gateway, fiber service, outage status, DNS or router handoff is failing.
Check Smart Home Manager and gateway status first. Then test your own router if you use one.
Can IP Passthrough cause no internet?
Yes. If passthrough points to the wrong device or your router fails to renew its WAN connection, the network behind it can lose internet.
Test the AT&T gateway by itself, then check your router's WAN address and passthrough settings.
Should I restart the AT&T gateway?
A normal restart is a good early step after checking app status. Let the gateway fully reconnect before judging the result.
If Smart Home Manager reports an outage or fiber issue, restarting repeatedly will not solve the provider-side problem.
Why does gateway Wi-Fi work but my router does not?
That means AT&T service is probably working and the issue is between the gateway and your personal router or mesh.
Check IP Passthrough, WAN cable, DNS and router mode before calling it a fiber outage.
Should I factory reset the gateway?
Factory reset should be late, not first. It can remove custom Wi-Fi, passthrough and firewall settings.
Use it only after status checks, restart, baseline testing and AT&T guidance.
Can AT&T Fiber fail after adding my own router?
Yes. The fiber service may be fine while the handoff to your own router is wrong.
Test the AT&T gateway alone, then check IP Passthrough, WAN cable and router DNS before changing every device.
When should I contact AT&T?
Contact AT&T if Smart Home Manager shows service trouble, the gateway cannot connect to fiber, or all devices fail even on gateway Wi-Fi.
If only your own router fails, troubleshoot the router handoff first.
Outside references
- AT&T Internet Support
Official AT&T internet support.
- AT&T Smart Home Manager
AT&T gateway and network management help.