Direct answer
For the Ubiquiti UniFi Cloud Gateway Ultra, provider modem/ONT, router WAN address, DNS and one client should be separated. First, check provider status and router WAN/link indicators.
What this covers
- Ubiquiti UniFi Cloud Gateway Ultra (UCG-Ultra)
- UniFi network; Network application version, gateway ownership, VLANs, PoE and adoption state are part of every diagnosis.
- The specific fault this record addresses: has Wi-Fi but no internet
What it does not cover
- ×The same symptom on a different Ubiquiti product line, which has its own record and its own cited source
- ×An on-screen error code whose meaning has not been checked against this exact model's manual
- ×Live electrical, gas, sealed-system, internal battery-cell or structural repair — a technician boundary, not a self-service step
Differential
What actually causes this, and how to tell them apart
These are ordered by how often each one is the answer, not by how easy it is to try. The point of the middle column is that two causes producing the same headline symptom rarely produce the same detail — that detail is what tells you which one you have before you change anything.
- 1
The provider's line or the modem/ONT is down
What separates it The modem or ONT shows an error light, is missing its online/link light, or the provider's status page reports an outage.
How to confirm Read the modem/ONT indicator lights against the provider's own legend, and check for a reported outage before touching the router — a dark 'online' light is a provider or modem problem the router cannot fix.
- 2
The router has no WAN (public) IP address
What separates it Devices get a local address and Wi-Fi shows connected, but the router's status page shows no WAN IP or a self-assigned one.
How to confirm Open the router's status page and read the WAN/internet address; a blank or 0.0.0.0 WAN means the router never obtained a lease from the provider, often fixed by a full modem-then-router power cycle in order.
- 3
DNS is failing while the connection itself is up
What separates it Numeric addresses load but named sites do not, or only some sites fail.
How to confirm Cross-check the DNS symptom; if the link is up but names will not resolve, the fix is DNS, not the WAN link.
Before you touch a setting
Record this first — changing settings destroys the evidence
Every item below stops existing the moment a reset, re-pair or settings change is made. Written down first, they are what separates the causes above; recovered afterwards, they are guesswork.
- The modem/ONT indicator lights and whether the provider reports an outage.
- Whether the router's status page shows a valid WAN/internet IP address.
- Whether a wired device and a second wireless device are both affected.
Check the provider status and the modem/ONT lights first
ReversibleA missing 'online' light or a reported outage is upstream of anything you can change.
Power-cycle the modem, then the router, in that order
ReversibleFully power off the modem/ONT, wait, bring it back to a solid online light, then bring the router up so it can pull a fresh WAN lease.
Read the router's WAN address on its status page
ReversibleA blank or self-assigned WAN IP tells you the break is between the router and the provider.
Confirm with a wired and a wireless client
ReversibleLoad a public site on both to prove the internet path is restored end to end.
Model-specific
What is true of this model and not of its siblings
Generic advice for the product line fails here. Each item below is a property of this specific model family that changes which of the steps above apply to you.
- Model scope
- UCG-Ultra. UniFi network; Network application version, gateway ownership, VLANs, PoE and adoption state are part of every diagnosis.
- Type — compact GATEWAY/router, NO Wi-Fi
- The UCG-Ultra is a small UniFi gateway (router, firewall, UniFi Network controller) with NO built-in Wi-Fi radio — it does not broadcast wireless. Wi-Fi symptoms do not apply; add separate UniFi APs. It is the compact, affordable way into the UniFi ecosystem.
- Needs separate access points
- 'No Wi-Fi' is expected — the Wi-Fi comes from UniFi APs connected to it (via a PoE switch/injector). Troubleshoot Wi-Fi at the APs.
- UniFi controller/app
- Runs the UniFi Network application on-device (managed web/app). Advanced compared with consumer routers.
- Symptom boundary
- This record covers Ubiquiti UniFi Cloud Gateway Ultra when it has Wi-Fi but no internet. A different symptom on the same hardware, or this symptom on a different Ubiquiti product line, has its own record with its own causes and its own cited source.
Stop boundary
When this stops being a self-service repair
Continuing past any one of these costs more than the repair saves — in safety, in warranty, or in evidence a technician needs.
- !Do not factory-reset a router or gateway to fix 'no internet' — it wipes your configuration and rarely addresses a WAN or provider fault. Do not expose admin credentials to anyone claiming to be the provider.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Where the manufacturer's article stops. Ubiquiti Help Center publishes this as "Troubleshooting UniFi Device Connectivity". Ubiquiti's own device-agnostic UniFi connectivity troubleshooting article. Verified reachable and content-matched via the Browser tool 2026-08-28. What that article does not carry is the model boundary — it is written for a product line, and UCG-Ultra is the scope applied here. Where a control label, terminal, indicator pattern or reset sequence differs on your unit, the manual for that exact model is the authority, not this page and not the article.
Exact questions
Common follow-ups
I set up a UniFi Cloud Gateway Ultra but have no Wi-Fi.+
That is because the Cloud Gateway Ultra has no built-in Wi-Fi radio — it is a compact gateway/router, not a wireless router. You need to add UniFi access points (such as a U6 Pro or U7 Pro), connect them (they need PoE, from a PoE switch or injector), and adopt them in the UniFi Network application running on the gateway. Once an AP is adopted and online, it broadcasts your Wi-Fi. The gateway itself only routes.
My Wi-Fi says connected but nothing loads.+
That split — a good device-to-router link but no internet — points at the router-to-provider side. Check the modem or ONT lights and the provider's outage page first, then power-cycle the modem and router in order (modem to a solid online light, then the router). Finally read the router's WAN IP on its status page: if it is blank, the router never got a connection from the provider, which is where to focus rather than resetting anything.
Does this answer apply to every Ubiquiti model?+
No. It is scoped to UCG-Ultra. UniFi network; Network application version, gateway ownership, VLANs, PoE and adoption state are part of every diagnosis.
What should I record before troubleshooting no internet or connected no internet?+
Record the complete model identifier, exact message or indicator, software/firmware where visible, the operating stage and what still works.
Why is a factory reset not the first step?+
A reset can erase accounts, networks, maps, schedules or preferences without distinguishing no internet, connected no internet. The ordered checks preserve that evidence.
When should I stop and use qualified service?+
Do not factory-reset managed gateways or expose admin credentials.
Answer for the exact device and software version shown above.