For a slow UniFi gateway network, separate the gateway from wifi. Ubiquiti's maximizing wireless speeds and WiFi troubleshooting articles cover the wifi side; on the gateway, first confirm the internet connection itself by testing a laptop cabled to the modem and comparing with the plan. A gateway with intrusion prevention, deep packet inspection or content filtering enabled routes more work through its CPU, and each model has a throughput limit with those features on, which techspecs.ui.com lists; the Cloud Gateway Ultra, for example, is a one-gigabit routing device.
The checks in more detail
Check the WAN link speed negotiated in the port LEDs: green means a link at 1000 Mbps, amber means 10 or 100 Mbps, so an amber WAN or LAN port points at the cable or the far end. Look at the client's connection: a wifi client with a signal below minus 75 dBm is slow no matter what the gateway does, and Ubiquiti's guidance is that above minus 60 dBm is excellent and below minus 80 dBm is likely to be unstable. Check for a saturated uplink from backups or cameras and use Traffic Identification or Traffic Rules to find the heavy client.
Update the Network application, since performance fixes ship with releases. If speed dropped after enabling a security feature, disable it as a test to see how much it costs, and decide whether the protection is worth the speed. Measure before and after each change. Run the same speed test to the same server at the same time of day, write the number down, change one setting and test again. UniFi networks tend to be complicated, with VLANs, firewall rules and security features layered together, so a single change can help or hurt without an obvious reason.
If you use a smart queue or bandwidth limits, check the numbers are set to your real plan speed, since a limit set too low is a common cause of a gateway that looks slow but is following its own rules. Remember that the throughput figure for a gateway assumes large packets and few rules; a busy rule set or many small flows lowers it, so a gigabit plan on a small gateway with IPS on may not reach the full figure.
Differential
Likely causes of “Ubiquiti UniFi gateways internet or Wi-Fi is slow”, and how to tell them apart
- 1
A slow line
What separates it The speed is slow even when a laptop is connected straight to the modem
How to confirm Call the provider, since the slow speed comes from the line and not from your gateway
- 2
A CPU-bound feature
What separates it The speed drops when IPS or content filtering is switched on
How to confirm Test with the feature switched off, and check the throughput limit for your model
- 3
A 100 Mbps link
What separates it The port light is amber, which shows that the link runs at only 10 or 100 Mbps
How to confirm Replace the cable, or use a gigabit port, and check that the light turns green
- 4
A weak wifi client
What separates it The speed is slow only over wifi because the client has a weak signal
How to confirm Improve the signal, or move the client closer to the access point
- 5
A heavy client
What separates it The uplink is saturated because one client uses most of the bandwidth
How to confirm Find that client in the traffic identification view, and limit what it uses
Before you touch a setting
Record this first — changing settings destroys the evidence
- Speed at the modem and through the gateway
- Which security features are switched on in the Network application
- The colors of the port lights on the gateway
- The signal strength that the slow client reports
Try in this order
0 of 7 completedTest at the modem
ReversibleTest at the modem by plugging a laptop in directly, and running a speed test.
Compare through the gateway
ReversibleCompare the result through the gateway, using a wired connection for the same test, and then test again to see whether it helped.
Check port LEDs
ReversibleCheck the port lights, remembering that a green light means a link at 1000 Mbps.
Test with IPS off
ReversibleTest with IPS switched off, to see how much difference the feature makes to the speed.
Check the heavy client
ReversibleCheck the heavy client using traffic identification, to see which device uses the bandwidth, and then test again to see whether it helped.
Check wifi signal
ReversibleCheck the wifi signal, and aim for a signal that is above minus 70 dBm at the client.
Update
ReversibleUpdate the Network application and the gateway, since releases include fixes for performance, and then test again to see whether it helped.
Model-specific
What is true of this model and not of its siblings
- Throughput
- Routing throughput with IPS on differs by model; check techspecs.ui.com.
- Ports
- The Dream Machine Pro and SE have SFP+ ports for faster links.
Stop boundary
When this stops being a self-service repair
- !If the modem tests fast and the gateway is slow with features off, contact Ubiquiti support
- !If only wifi is slow, follow the wifi guide
- !If a port is stuck at 100 Mbps, replace the cable
Evidence ledger
Sources behind this answer
Wireless speed tuning.
Signal strength, AirView and channels.
White, blue and port LEDs.
Update Manager, auto-updates and update troubleshooting.
The company and its products.
Exact questions
Common questions
Can security features slow my gateway?+
Yes, each model has a throughput limit when the security features are switched on.
What signal is excellent?+
A signal above minus 60 dBm is excellent, and is the level you should aim for.
What signal is unstable?+
A signal below minus 80 dBm is unstable, and clients will drop or slow down.
How do I find a heavy client?+
Use traffic identification in the Network application, to find out which client is heavy.
Is the Cloud Gateway Ultra a gigabit device?+
The Cloud Gateway Ultra is described as a 1 Gbps routing gateway, so it tops out near that.
Can the modem be the limit?+
Yes, the modem can be the limit, so test with a laptop plugged into it.
Where are the throughput numbers?+
The throughput numbers for each model are at techspecs.ui.com.
Which TCP port must the device reach the application on?+
The device must be able to reach the application on TCP port 8080 for adoption and management.
Where is Update Manager?+
Update Manager is in Site Manager at unifi.ui.com, and it is also in the mobile app.