Ubiquiti Wireless Network

7 Reasons Why Choosing Ubiquiti

as your preferred Wireless (Wifi) Solution

Low Price

Ubiquiti Disruptive Low Pricing Model

has succeeded in gaining market share

Enterprise Grade

Low-price and high-quality Product has made

Ubiquiti products stand up to Cisco, Aruba, Meraki

No Subscription Fees

No Subscription or licensing or software fees

to upgrade. The software upgrades are all FREE

Modern Design

Simple and clean design syncs beautifully with your space 

Easy to Manage

Almost anyone can set up this system up without any problems

Scalability

Fast, stable and reliable.

Scalable up to unlimited AP’s and control from 1 location

Advanced Wireless Controller

Supports Zero Handoff, Custom Maps,

Google Maps, Hotspot Manager,

Portal Customization, Guest Network,

WLAN Group

UniFi® AP AC PRO

802.11ac PRO Access Point

The UniFi AC Pro AP features the latest Wi-Fi 802.11ac, 3×3 MIMO technology in a refined industrial design and is ideal for deployment of maximum‑performance wireless networks.

Models: UAP‑AC‑PRO

UniFi® AP AC LR

802.11ac Long Range Access Point

The UniFi AC LR AP features the latest Wi-Fi 802.11ac technology in a refined industrial design and is ideal for long-range deployment of high‑performance wireless networks.

Models: UAP‑AC‑LR

UniFi® AP AC LITE

802.11ac Dual Radio Access Point

The UniFi AC Lite AP features the latest Wi-Fi 802.11ac technology in a refined industrial design and is ideal for cost-effective deployment of high‑performance wireless networks.

Models: UAP‑AC‑LITE

UniFi® AP AC EDU

802.11ac Dual-Radio AP with Public Address System

Featuring the latest Wi-Fi 802.11ac, 3×3 MIMO technology, the UniFi AC EDU AP conveniently integrates Wi-Fi and public address capabilities, making it ideal for campus-wide deployment.

Models: UAP‑AC‑EDU

UniFi® AC MESH

802.11AC AP with Plug & Play Mesh

High-Performance Wide-Area Wi-Fi with UniFi® Mesh Technology
Breakthrough Speeds up to 1300 Mbps in the 5 GHz Band
802.3af PoE Compatibility

Models: UAP‑AC‑M

UniFi® AC MESH PRO

802.11AC AP with Plug & Play Mesh

High-Performance Wide-Area Wi-Fi with UniFi® Mesh Technology
Breakthrough Speeds up to 1300 Mbps in the 5 GHz Band
802.3af PoE Compatibility

Models: UAP‑AC‑M-PRO

TOUGHSwitch™

Advanced Power over Ethernet Switches

The TOUGHSwitch delivers reliable passive PoE and Gigabit connectivity to attached Ubiquiti devices and other devices that support passive PoE.

Models: TS‑16‑CARRIER, TS‑5‑POE, TS‑8‑PRO

EdgeSwitch™

Managed PoE+ Gigabit Switch with SFP

Available with 24 or 48 RJ45 Gigabit ports, the EdgeSwitch delivers robust performance, PoE+ support and intelligent switching for growing networks.

Models: ES‑16‑150W, ES‑16‑XG, ES‑24‑250W, ES‑24‑500W, ES‑48‑500W, ES‑48‑750W, ES‑8‑150W

Compare Ubiquiti UAP-nanoHD, UAP-AC-Pro and UAP-HD

Compare Ubiquiti UAP-AC-Pro, UAP-NanoHD, UAP-HD

UAP-nanoHD

  • is smallest and thinnest of the three models
  • can be skinned to conceal in the ceiling
  • is positioned between UAP-AC-PRO and UAP-HD.
  • is only for indoor use with 1 single LAN port.

Type of Power Over Ethernet (POE) Class

  • 802.3af POE  (Max 12.95W)
  • 802.3at POE+ (Max 25.5W)
  • 802.3bt POE++ (Type 3 – Max 60W, Type 4 – Max 100W)

Sleek Industrial Design

Featuring a clean industrial design, the UniFi®AP can be integrated

seamlessly into any wall or ceiling surface (mounting kits included).

The LED indicator simplifies deployment and configuration.

Scalability for Thousands

With its software-based capabilities, the UniFi®virtual control plane allows for unlimited scalability under one centralized controller.

Rapid Deployment

Plug and Play installation and intuitive management reduce the need for dedicated IT personnel resources.

Amazing Long-Range Links

The UniFi®AP-LR offers a longer range – up to 183 m – than the base model UniFi AP or UniFi AP-PRO.

Simultaneous Dual-Band Wi-Fi

The UniFi®AP-PRO supports up to 300 Mbps,

2×2 MIMO for the 5 GHz band and up to 450 Mbps, 3×3 MIMO for the 2.4 GHz band.

Scalable Enterprise Wi-Fi Management

The UniFi®Controller software is a powerful, enterprise wireless software engine ideal for high-density client deployments requiring low latency and high uptime performance.

A single UniFi Controller running in the cloud can manage multiple sites: multiple, distributed deployments and multi-tenancy for managed service providers.

Advanced Software Features

 

Intuitive and Robust Configuration, Control and Monitoring
Instantly provision and configure thousands of UniFi®APs. Quickly manage system traffic.

Custom Maps and Google Maps
Upload custom map images or use Google Maps for a visual representation of your wireless network.

WLAN Groups
Take advantage of WLAN groups for flexible configuration of large deployments and enable wireless connection between APs to extend range.

One UniFied Network with Zero-Handoff Roaming
Create one large wireless network across multiple APs so users can roam and seamlessly maintain their connection as they switch to the nearest AP.

Frequently Asked Questions (FAQs)

UniFi - Troubleshooting Client-Specific Connectivity Issues

Introduction


In some cases, users may encounter issues with certain client devices being unable to connect to Wi-Fi or have specific performance issues that appear to only coincide with certain segments of devices. For example: Android phones cannot connect to my UniFi network or iOS devices frequently disconnect on my network. These can be confusing and difficult issues to solve for network administrators especially since in many cases the root issue can be difficult to identify.

To most quickly identify and resolve these issues, users need to identify the common threads/scope of the issue and use that to narrow down to a root cause. This article will explain how to approach issues like these and list some common causes.


Understanding Device Compatibility


When a client device connects or fails to connect to a UniFi network, the process on the UniFi side is relatively simple and straightforward. This doesn’t change for each individual type and variety of client. UniFi has millions of APs in deployment that work with all manner of client devices without issue. Additionally, UniFi does performance tests on hardware with a variety of client devices to ensure proper function.

Outside of UniFi, there are many variables involved with all the different devices, network drivers, wireless adapters, etc. that often go unnoticed/aren’t frequently considered. In most cases, issues assumed to be UniFi issues that are confined to a segment of client devices end up to be totally unrelated to UniFi. In some cases, you can change your UniFi configuration to help adapt your network to the limitations of your devices. For instance, fast roaming may not work well with all client devices depending on how old they are, how these products roam by default, etc.

When an issue like this occurs, it’s important to narrow the issue down as much as possible to different client devices, software versions, etc. so that you know where to look for the solution. Here are some good questions to ask when encountering such issues:

  • How many devices are affected?
  • What do these devices have in common? Location? Device hardware? OS version?
  • When did the issue start occurring?
  • Does it occur in all cases or is it intermittent? Is the issue consistently reproducible?
  • Is there an error message?

Many users mistakenly attribute any issue they encounter on a Wi-Fi network to the hardware connecting the devices or the internet service provider, using proper troubleshooting and not assuming a particular explanation will help you resolve issues as quickly as possible.


Tips/Suggestions


Here are some suggestions for resolving client specific issues with Wi-Fi:

  • Verify user-reported issues yourself- most often the cause for individual client Wi-Fi issues that are unreproducible by others is user error with WPA key entry or similar issues.
  • Make sure client has high signal strength and eliminate interference from the equation if at all possible.
  • Reboot client devices first when a small number of individual client devices are affected.
  • Try updating wireless adapter drivers on client devices when a subset of devices with same wireless adapter are malfunctioning, or in individual cases.
  • Once you’ve arrived at an understanding of what the behavior is and confirmed it, perform a web search for similar error messages/behaviors from similar client devices- if the device affects all Android devices for instance, you’ll certainly find mention of in threads unrelated to UniFi. Follow steps and contact the device vendor for help.
  • In individual cases where an issue proves difficult to resolve, scan the device for any malware that could be causing connectivity issues.
  • Try eliminating any advanced features like RADIUS or fast roaming from your UniFi Configuration to ensure that they haven’t been improperly configured or that your devices do not support such configurations. Set up a parallel, simplified Wi-Fi network with as few modifications to default config as possible to see if issue is eliminated.
  • Use packet captures to monitor traffic to help identify root causes.
  • Search on community.ubnt.com for similar issues or post asking for suggestions.

When issues affect all devices, this implies that the issue is more likely to be a result of poor configuration or a potential performance issue on the UniFi side. If you encounter issues that are reproducible across all subsets of devices and appear to be related to UniFi and its function, please post on our community or contact UniFi support for additional help.

UniFi - Troubleshooting Slow Wi-Fi Speeds

Introduction


One of the most common Wi-Fi performance concerns reported is slower than expected Wi-Fi speed. This is due to a number of factors:

  • Speed issues can result from wide range of network limitations and problems- many of which have nothing to do with wireless.
  • Declined speed is easy to notice in typical network usage.
  • Internet speedtests are the most widely—and sometimes the only tool used to evaluate/benchmark network performance: and can be inconsistent and inaccurate.
  • ISPs and hardware vendors market products with peak theoretical performance that differ from real-life usage.
  • It’s hard for users to know what speeds they need and should expect.

This article will help users better understand what Wi-Fi speeds to expect, resolve common issues and optimize their Wi-Fi configuration.


Measuring Wi-Fi Performance 


When looking at Wi-Fi performance it is important to take a step back and consider how Wi-Fi is supposed to work. Wi-Fi offers benefit of mobility, scalability and convenience over wired networks at the expense of maximum throughput and stability. With respect to client performance, modern Wi-Fi is designed to allow clients to enjoy the benefits of not being tethered to a wired network, while preventing any visible reduction in performance across its area of coverage.

Much of the concern about wireless throughput comes from a lack of understanding about how much bandwidth clients actually use. The difference between 300 Mbps and 500 Mbps may seem significant but the difference in performance would likely never be noticed through client use.

Here are estimated requirements of what throughput client devices need to use without declined performance (for more info see here):

Client Application-specific Bandwidth Requirements

ApplicationPotential Peak ThroughputAvg. Throughput Used
Web Browsing/Email (Light)1 Mbps.25 Mbps
Web Browsing/Email (Moderate)2 Mbps.5 Mbps
Web Browsing/Email (Heavy)4 Mbps1 Mbps
Apple Facetime Video Call (HD quality).7 Mbps.7 Mbps
Skype Group Video Call (7+ people)8.5 Mbps8.5 Mbps
Netflix Video Streaming (HD Quality)5 Mbps5 Mbps
Netflix Video Streaming (Ultra HD Quality)25 Mbps25 Mbps

UniFi’s products are designed and tested to ensure they can provide for this typical use for many clients simultaneously. Any Access Point (AP) currently being offered in the UniFi product line offers far greater potential throughput than any client application could realistically require.

If a UniFi Access Point fails to provide the speed that it is capable of, this is most often a result of environmental limitations or other bottlenecks in the deployment. UniFi provides many tools that can help users identify these factors and mitigate them with proper configuration.


Prerequisites 


The rest of this article assumes that the following prerequisites have been met:

1. Eliminate any Bottlenecks

Before working to improve your Wireless performance, it’s important to identify any bottlenecks outside of your Wireless network. A bottleneck is the point in a network infrastructure that limits performance everywhere else. Often poor Wi-Fi speed is incorrectly assumed to be a result of Wi-Fi hardware/config, but actually is the result a bottleneck upstream from the device. Here are some common examples of bottlenecks:

  • ISP Plan limits performance/speeds far beneath what Wi-Fi is capable of providing. For example a plan might have a 100Mb/25Mb down/up bandwidth limit on service. Every UniFi device, including legacy devices, is capable of far exceeding this limit. See image below.
  • Far too few APs for the number of clients/coverage requirements.
  • Old/faulty ethernet cables.
  • Outdated LAN hardware.
  • Outdated Wireless hardware.
  • Legacy client devices that don’t support 5GHz.
  • Too much noise on a single channel.

The following is an example of a common network bottleneck:

bottleneckdiagram.PNG

Diagram illustrating how Wi-Fi speed test results can be limited by ISP 

An easy way to at least rule out any bottleneck is plug a wired device into the secondary port on an AP and perform the same speedtest you are using to test Wi-Fi performance and compare the results to each other. It is normal to see some diminished performance on wireless compared to wired speedtests, but make sure you at least know what your wired network is capable of providing to the AP.

2. Update UniFi Controller and UniFi Access Point (AP) Firmware to Current Version

Ubiquiti’s Firmware updates often include performance improvements: make sure that before testing performance, you update your UniFi Controller and UniFi Devices to the most current firmware available.


Common Issues/Steps to Fix


This section examines some of the most common issues that cause diminished speeds on UniFi Networks, as well as the steps that will solve them.

Channel Width

Channel width is the most common cause for poor speed test results after setting up UniFi, especially when being compared to a single wireless router the UniFi devices are replacing. Default UniFi config on 5GHz radio is optimized for large environments (40MHz channel width), while most standalone routers are optimized for use as the only AP in a home/office (80MHz).

To properly test maximum speed of a UniFi AP, switch to 80 MHz. 80 MHz channels are capable of more than double the peak speed of 40 MHz channels.

NOTE: These settings only apply to 5GHz. We do not recommend that channel width be increased from 20 MHz on 2.4GHz as this will often cause worse performance.  

To change AP to use 80MHz channel width, go to Devices > Click on AP to open Properties Panel > Radios RADIO 5G (11N/A/AC), Change Channel Width from VHT40 to VHT80, click Queue Changes, then Apply Changes. 

2018-11-30_21-57-20.gif

Summary: If using a small number of APs, switch 5GHz channel width on APs to 80 MHz for greater peak throughput. In larger environments, note that 40 or 20 MHz channel width is recommended for performance but can limit peak throughput.

Interference/Channel Overlap

The single most potentially negative environmental factor for Wi-Fi performance and stability is wireless interference. Interference can come from external sources like other wireless networks, weather radar, etc. while internal interference can come from devices overlapping with each other on the same channel.

By default UniFi Devices are set up with auto channel assignments, but this is something you will want to adjust for your deployment if there are concerns about speed/performance.

It is recommended that a full site survey be performed for high density/high priority Wi-Fi deployments. If that has not been done or the site doesn’t warrant it, the UniFi Controller can help you find a better channel assignment for your APs by performing an RF scan.

To do this, go to Devices > Click on AP to open Properties Panel Tools > RF Environment and click Scan.

NOTE: Running an RF Scan will disconnect any wireless clients currently connected to the AP. Do not run during peak hours if this is a concern.

This scan will take 5-10 minutes, and will populate the 2.4GHz channels first and then 5 GHz channels will subsequently be updated.

Once your RF scan is finished, select 5G and you’ll see a list of channels arranged by channel width and how much each channel is being utilized. Select a channel that appears to have the least noise on it and assign your AP to this channel.

To do this go to Devices > Select AP > Properties > Radios RADIO 5G (11N/A/AC), and choose the desired channel.

If using multiple APs, make sure that each AP does not share the same channel as a nearby AP, and avoid having channels that are adjacent to each other as this can also cause interference.

pasted_image_0__1_.png

Summary: Interference/channel overlap can cause performance to decline. To make sure speedtest results are not being impacted by interference, make sure APs are assigned to the optimal channel and not sharing or adjacent to the channel of any nearby APs.

Signal Quality

Another factor that can strongly influence Wi-Fi speed is signal quality between AP and client device. As clients get further away from an access point and signal gets weaker, to ensure stability/offer best possible performance, the AP will lower the rate of the data transfer to compensate.

When testing peak throughput, be sure to be standing close enough to the AP without obstructions and make sure the client signal strength is close to the maximum of 99%. If your client devices consistently have poor signal strength on 5GHz try increasing Transmit Power on 5GHz.

To increase TX power on 5GHz, go to device configuration > Radios Radio 5G (11N/A/AC), and only select “High” from the dropbox under Transmit Power.

NOTE: Increasing transmit power on devices can have undesired effects, especially in a very high density environment. Consider starting from a low baseline and increasing as needed on a per-AP basis.

Summary: When testing throughput make sure to consider the signal strength between the device and AP, you can find this under the Clients tab in the UniFi Controller. If range on 5GHz is very low, consider increasing Transmit Power on the AP’s 5GHz radio.

Inconsistent/Inaccurate Speedtest Methods

Another cause for poor speedtest performance is inconsistent or inaccurate data. When comparing across devices, make sure to use the same speedtest method as different speed test apps can vary wildly.

While UniFi does include a speedtest, the results are often far lower than reality, especially since UniFi’s available speedtest servers are limited and results are very sensitive to proximity of the speedtest server. Try using a popular speedtest app or website to test to check your UniFi results. Be sure to test multiple times and do not rely on assumptions or past data to inform your comparison.

If you wish to most accurately assess Wi-Fi speed alone and rule out other factors, try performing an iPerf test between a wired and wireless client/between two wireless clients. iPerf only measures bandwidth between two devices on your network. Note that iPerf can still be limited by the syntax you can use, number of streams, packet size, etc. so make sure you understand what you’re doing before using iPerf.

Summary: Speedtest results are often inaccurate. Make sure to use consistent speedtest methods when comparing between devices, wired vs. wireless, etc. Confirm/test using multiple platforms. UniFi speedtests are often less accurate than other more popular speedtest apps

Client-specific Issues & Limitations

When benchmarking Wi-Fi, it’s important to also compare across devices to ensure that the client itself isn’t limiting performance. Factors like client CPU utilization, network card driver, Wi-Fi specs, software, all can influence speed test results.

Make sure to test with multiple devices. To truly measure peak throughput you must test a device that matches the capabilities of the UniFi AP. For instance, if you are testing with a device check the manufacturer specifications to see how many streams the 5GHz antenna supports i.e. Apple iPhone 7 is 2×2, UAP-AC-PRO has 3×3 5GHz radio, thus this iPhone will limit peak throughput.

If a performance issue with Wi-Fi is isolated to one device, or multiple devices running the same software version, this will almost always point to a problem with the device/software. UniFi doesn’t change how it functions for each variety of client device. Try performing a web search to find other users experiencing similar issues with the same device on other vendor products.

Keep in mind that declined performance on a single device isn’t a sign of a malfunctioning AP. UniFi APs are backwards compatible with older client devices and the fact that devices are able to connect with their older hardware is a sign the AP is working as designed.

Summary: Test multiple client devices when benchmarking Wi-Fi performance. Client specific issues are common but are largely unrelated to AP configuration/hardware.

UniFi - Troubleshooting Connectivity Issues

Introduction


The most common intermittent connectivity symptom is a laptop or mobile phone showing full WiFi signal, but when using network services/browsers, no sites or pages load. Browsers will sometimes report no Internet connectivity, but will also sometimes spin forever loading pages. Sometimes an exclamation point will appear with the WiFi bars, and sometimes the client device will select an auto-assigned IP (such as 169.254.x.x) for its IP address on the LAN.

Many of these types of issues have been fixed in recent UAP firmware releases, so please ensure that you are using the latest firmware release for your devices before investigating further. See this article for how to update device firmware. This article offers suggestions for debugging and fixing these types of issues for a smooth Internet/network experience.


Wired or Wireless?


First and foremost, it is important to determine whether the problem lies in either the wired or the wireless infrastructure of the network. Try to continuously ping Google’s public DNS (8.8.8.8) and your router simultaneously from two terminals on a laptop. If there is packet loss to both IPs, then you likely have a wireless issue. If there is only packet loss on 8.8.8.8, then you likely have a wired/Internet issue. This article focuses on resolving wireless issues only, not wired issues.

Please note that many laptops enable WiFi power-saving mode on their WiFi interface, regardless of whether the laptop is charging or not, and you may see ping responses up to 1.25 seconds late, especially if the laptop is not busy doing anything else on the network. This is designed by laptop manufacturers to conserve power, and this article will focus particularly on resolving packet loss , not packet latency.


Check your Configuration


The following AP network configuration, as seen on the access point’s properties panel has three errors. Can you spot them?

  1. The subnet mask is too narrow to provide a route to the gateway.
  2. The Gateway itself is not on the same subnet as the static IP address.
  3. There is no Preferred DNS configured.

Misconfiguration can lead to inability to upgrade UAPs, NTP sync failure, among many other intermittent issues that are difficult to diagnose. For the best experience, it is important to ensure that all UAPs have full citizenship on the network, including DNS access and Internet-routability.


AP Proximity


Try moving closer to the UAP that your client is associated to, to verify if the problem goes away. If the problem is resolved, then you may need to re-assess the locations and count of your UAP deployment.


Network Loops


Network loops can easily be detected by running tcpdump on the affected UAP and/or UniFi Switches, and by viewing the output in Wireshark. Do so by following these steps:

1. SSH into the affected UAP, and issue the following command:

tcpdump -i br0 -n -v -s 0 -w /tmp/capture.pcap

2. Then copy the resulting pcap file to your laptop for viewing in Wireshark.

scp [email protected]:/tmp/capture.pcap /tmp

This copies the capture.pcap to /tmp on your computer. You can also use winscp similarly.

3. Now open the file in Wireshark.

If there is a network loop somewhere, you will see a large amount of multicast or broadcast traffic in the capture file. Typical networks will have less than 100 kbps of multicast/broadcast traffic, totaling only dozens of packets per second. If there are thousands of multicast/broadcast packets per second, then you likely have a network loop somewhere that needs to be resolved. Keep disconnecting infrastructure devices until the number of multicast/broadcast packets goes down to a reasonable number.


Link Budget


The high transmit power (TX power) of UniFi APs is great for single-AP installations, but can be problematic in enterprise/multi-AP deployments. The high TX power will extend the range for slower TX rates only, as faster rates are transmitted at a lower TX power, which is normal for ALL APs and devices. This eats up air-time for faster rates in multi-AP deployments, slowing down the entire network and potentially causing packet loss.

High TX power also causes an imbalance in the WiFi link budget between the mobile client and the UAP, because most mobile clients have a TX power between 14 and 18 dBm. Mobile clients will stay connected (and show full WiFi bars) to an AP with a strong signal from the AP to the mobile client, even if the signal from the mobile client to the AP is not sufficiently strong.

Lowering the TX power on the UAPs to 18 dBm or so will establish a more symmetrical link-budget for most devices and deployments. This can easily be done in the Controller UI.


Disabling Features


Some features such as band-steering, minimum RSSI, and connection monitor can cause adverse effects if misconfigured or implemented with an insufficient number of APs. It is good to disable all of these features when debugging connectivity problems so that base functionality can be verified without any extra variables. The AirTime-Fairness feature can also be disabled to bring base functionality to the bare minimum.


DHCP Configuration


Some older/misconfigured routers and DHCP servers transmit the DHCP offer/ack messages as broadcast packets, which are much more likely to be dropped. This can lead to slow connection times and intermittent connectivity. Please ensure that your DHCP offers and ack messages are unicast packets, not broadcast (the discover packet from the client can still be broadcast).


Modifying the DTIM Period


A default DTIM period of 1 is used for compatibility and legacy reasons. However, many modern devices including recent iOS and Android phones, will perform better and save up to 66% of their WiFi battery consumption if the period is set to 3. For networks with nearly all modern devices, it is recommended to use a DTIM period of 3 instead.


Wireshark – Packet Capture


Wireshark can be downloaded for most platforms at www.wireshark.org. Modern (2013+) MacBooks are recommended as they 1) have full driver-support for monitor mode, and 2) have premium 3×3 radios that are capable of hearing 3 NSS traffic (up to 1300 Mbps physical rate). Linux can also be used with some laptops, but most laptops only have 2×2 radios, so they are less useful.

  1. Download/install Wireshark.
  2. Open Wireshark.
  3. Click on the gear icon at the top.
  4. Ensure that monitor mode is enabled for the en0 interface: 
  5. Click Close, and restart Wireshark.
  6. Start a capture on en0. You should see beacon, control, and management frames interspersed with data frames.
    NOTE: At the time of writing this article, there was a bug in Wireshark where capturing in monitor mode would fail the first time it was enabled, unless Wireshark was completely restarted first.

    You can upload this capture to the community or to UBNT support, and be sure include the MAC address of the laptop or mobile device that is having issues.


Trace Packets Through the Network


In some cases, multicast/broadcast packets can be successful whereas unicast packets are not. It is important to understand which type of packets get how far on the network. You’ll need to determine which “VAP” interface your wireless client is connecting to first. You can ssh into the problematic AP and issue:

iwconfig

In the above example, you can see that ath6 is the VAP for the ubnt-ut-AP-LR network on the 5 GHz radio.

Determine if Broadcast Packets are Reaching the UAP

1. To see if broadcast packets are making it to your UAP, run tcpdump on the athX interface on the UAP (SSH on UAP):

tcpdump -i athX -n -v -s 0 -w /tmp/broadcast.pcap

2. Send some broadcast packets using ping from your laptop (terminal on laptop):

ping 192.168.1.255

3. Stop the capture, and start another capture named /tmp/unicast.pcap (ssh on UAP):

tcpdump -i athX -n -v -s 0 -w /tmp/unicast.pcap

4. Next, try to send unicast packets to your router (terminal on laptop):

ping 192.168.1.1 (replace with your router’s IP)

5. If broadcast packets aren’t being transmitted or received, then the unicast packets won’t go out (due to a missing ARP entry in the OS), either, and you’ll need to force a static ARP entry into your laptop (terminal on laptop):

sudo arp -s 192.168.1.1 00:00:00:00:00:01 ifscope en0 (Mac OS X)
arp -s 192.168.1.1 00-00-00-00-00-01 (from Administrator Command Line in Windows

6. Try the ping again, and see if the 00:00:00:00:00:01 unicast packets arrive at the athX interface on the UAP.

Determine if Packets from the UAP are Reaching the Client

After you’ve determined whether there is packet loss from your client to the UAP, now it is time to determine if there is packet loss from the UAP to your client.

1. First, you will need to start Wireshark or tcpdump on your laptop to validate whether packets are getting to your laptop.

2. Then start a broadcast ping from your UAP to the network (ssh on UAP):

ping 192.168.1.255

3. Capture the results in wireshark/tcpdump, then start a ping to your laptop (ssh on UAP):

ping 192.168.1.X

4. At the time of writing, UAPs do not have a way to set a static ARP entry, so if unicast traffic can’t be produced from the UAP, you can try producing the packets by setting a static ARP entry on a wired desktop/laptop, then sending the packets from that separate device.

You can give the capture results to the community and/or a UBNT employee to help diagnose where packet loss is occurring.

5. Lastly, it is good to double-check that the bridge is configured correctly (ssh on UAP):

brctl show

The output should look similar to this:

Bridge NameBridge IDSTP EnabledInterfaces
br0ffff.44d9e7f9876anoath0

ath1

ath2

ath3

ath4

ath5

ath6

ath7

eth0


Are the APs Rebooting?


Check the uptime of the APs to make sure they aren’t rebooting. Uptime can be checked by clicking on the UAP in the Devices section and seeing the Details > Overview section  of the Properties Panel. Or in the Uptime column if the Devices section is in list view. If the uptime keeps getting reset, and coincides with network downtime, then you may have uncovered a bug, and we’d love to know how we can reproduce the problem in our labs. Let us know via our Community.


Check Your Hardware


There is always a small chance that hardware could have been damaged as there are many hands that your UAP has passed through from our factory to your desk. For cases where major packet loss cannot be resolved, regardless of what firmware you try, please continue reading.

It is best to set your 2GHz and 5GHz radios up on separate SSIDs, and even better to set both of them to different SSIDs from all other UAPs, for testing purposes. For example, if your network name is “HomeNetwork”, set the 2GHz SSID to “HomeNetwork-test2” and 5GHz SSID to “HomeNetwork-test5” so that they don’t conflict with each other or any other SSID. If you have more than one SSID per radio, you only need to test one SSID per radio, so you only need to modify one of the SSIDs per band, not all of them.

1. After getting your SSIDs in order, please SSH into, and issue the following commands on your UAP:

iwpriv wifi0 get_txchainmask

This will give you the number of chains available on radio 0. This is a mask, so 3 means you have 2 chains, 5 means you have 2 chains, 7 means you have 3 chains, 15 means 4 chains, etc.

2. Run the command again for the second radio on your UAP (if your UAP is dual-band):

iwpriv wifi1 get_txchainmask

3. Now we will test each of the chains on your UAP. This will test chain 0:

cm=1; for a in 0 1; do for b in tx rx; do iwpriv wifi$a ${b}chainmask $cm; done; done; killall hostapd

4. Use “WiFi Analyzer” or some other app to view the signal strength of the UAP’s beacons on chain 0 for both 2 GHz and 5 GHz. You should be standing within 10 feet of the UAP, and if the signal strength is lower than -60 dBm, you may have an issue with that chain.

5. Try the other chains as well:

cm=2; for a in 0 1; do for b in tx rx; do iwpriv wifi$a ${b}chainmask $cm; done; done; killall hostapd

6. View the signal strength on chain 1. Then:

cm=4; for a in 0 1; do for b in tx rx; do iwpriv wifi$a ${b}chainmask $cm; done; done; killall hostapd

Keep in mind that cm=1, 2, and 4, correspond to chains 0, 1, and 2, and if your UAP does not have chain 2, then you will not see any signal on that chain (and this is normal!)

7. Next, reboot the UAP to get the chains back to normal. Connect a known-good laptop within 10 feet of your UAP. Run iperf3 on a wired server (Linux, Mac, Windows OK) with:

iperf3 -s

8. Then run iperf3 from your WiFi connected laptop/mobile device:

iperf3 -u -c SERVER_IP -b 50M -R

9. Then run in the opposite direction.

iperf3 -u -c SERVER_IP -b 50M

10. Broken hardware will typically get far less throughput in one direction than the other (i.e. 50 Mbit one direction, and 0 the other). If this is the case, please @mention a UBNT employee in a forum topic for confirmation and next steps.

UniFi - How to Reset the UniFi Access Point to Factory Defaults

UniFi Controller Reset


If the UAP has been adopted by the UniFi Controller, it can be reset from the controller. Do so by “Forgetting” the device.

  1. Log in to the UniFi Controller. In the Devices page, click on the UAP you wish to reset. This will open the Properties panel.
  2. Select the Configuration tab, and click Manage Device to expand.
  3. Click the Forget button. This will erase all configuration and history for that device, effectively resetting it.

SSH Reset


Access the UAP via SSH, and once in, issue the commands syswrapper.sh restore-default and hit enter. The UAP should quickly reboot with factory default settings. Remember to not disconnect UAP from power source during this process. See Related Articles below if you need guidance on how to SSH into a device.


Physical Reset


On the back of the UAP there is a small hole whereby a user can use a paperclip to depress a button and reset the UAP back to its factory default settings.

  1. Press and hold the reset button for 10 seconds while AP is connected.
  2. Release the button (the LEDs on the UAP will stop glowing).
  3. Do not disconnect the UAP from its power source during the reboot process.
  4. The UAP will restore factory settings.

Once the white LED (or amber LED, depending on your model) re-appears and remains steady, you can commence with UAP adoption once more.

NOTE: The location of the reset button might vary on different UAP models, find your device’s in the Quick Start Guide. You can download the current Quick Start Guide in https://www.ubnt.com/download/unifi/ using the left hand menu to find the correct product and scrolling down to the Documentation section.

 

UniFi - Identifying Wi-Fi Issues with Debugging Metrics

Introduction


The Debugging Metrics page shows a collection of data that makes it easier to identify and fix common Wi-Fi performance issues. To access Debugging Metrics on current UniFi Controller versions navigate to Statistics > and select Debugging Metrics from the dropdown. The Debugging Metrics section will include the following data tables:


  • Most Active APs
  • Retries
  • Channel Utilization
  • Top Clients
  • Top Interference
  • Most Active Clients
  • Longest Connected Clients
  • Top Memory Usage
  • Top CPU Usage
debugging.png

Each category contains a table that summarizes the data and can display information on the 2.4GHz band or the 5GHz one. In order for this feature to be available, users need to have at least one UniFi Access Point (UAP), although the data will be much improved with the use of a UniFi Security Gateway (USG) and UniFi Switch (USW). The following sections will explain the different fields of the Debugging Metrics view, giving network administrators the tools needed to resolve Wi-Fi issues they might encounter.


Most Active APs


This view lists the access points (APs) on the network that are sending/receiving the most traffic. Tx indicates packets transmitted, and Rx indicates packets received. At a glance, an administrator can identify if there are areas of higher demand that could benefit from having another AP available. Excessive use of an AP can lead to over-utilized memory/CPU, as well as poorer performance for over-active APs.

Common Causes & Solutions:

  • Not enough APs to meet density demands: If traffic appears consistently too high on a given access point, add an additional AP to help handle the traffic. Alternatively, consider placing nearby APs closer to the over-utilized AP to help handle some of the client load.
  • Problematic Clients: Sometimes what may look like an over-active AP may be more the result of a client device using up excessive traffic with P2P applications, media streaming, intentional spamming, etc. Identify clients that use too much traffic; and if applicable, use Deep-Packet Inspection (DPI) to identify whether the traffic being used violates what is acceptable terms of use of the network. You can then decide to either limit the problematic client by adding it to a client group with controlled bandwidth limits or to block it altogether.
  • Poor Configuration on AP: If an AP has a Tx power that is set too high and nearby APs are set too low at lower levels, one AP can attract client devices with better signal strength but fail to deliver optimal Wi-Fi experience. To fix this, make sure all nearby devices are sharing the load with the over-active AP. Additionally, test lowering the Tx power on the active AP; and raise it on the nearby, less active APs. This can be accomplished through the device property panel under the Radio section.

Retries


This view exposes the retry rate for both transmitting (packets that had to be resent to the client) and receiving (RX) packets (packets that had to be resent to the access point). The Retry rate indicates packets that had to be re-sent because they were corrupted upon arriving at the proper destination.

Common Causes & Solutions:

  • Interference: This is the most common cause of packet loss/retransmissions. Identify whether the Retry rate is higher on one of the two bands: 2.4GHz or 5GHz, or if it is equally impacted on both. Then look for other nearby APs to see how local the interference is. This can point to a rogue access point, a very congested RF environment, a problematic client device near the AP, etc. To solve, perform an RF Scan, and place APs on less congested channels. Also, eliminate adjacent channel overlap on nearby UniFi APs. Another option would be to identify a problematic device causing the interference and re-configure/remove it.
  • Client/AP Tx Power mismatch: Another common cause of packet retries is the mismatch of broadcast power levels (Tx Power). If an AP and client device are communicating at much different broadcast strengths, then this can cause packet retries. Look for packet retries on Rx specifically as this would indicate the more likely issue of the AP broadcasting too strongly for ideal behavior with the client.

Channel Utilization


This view reveals which APs are utilizing the most of their assigned channel on 2G or 5G. This section also shows what portion of the utilization is due to the AP itself.

Common Causes & Solutions:

  • Interference: If there is an access point with 59% Channel Utilization but only 15% combines Self Tx/Rx, this can indicate channel re-use/interference is the culprit. In a high-density environment, make sure you are minimizing the number of APs using each respective channel.
  • Legacy Clients/Poor Data Rates: If high channel utilization is seen on an AP that largely comes from Self Tx/Rx, check the Most Active APs table to see if it is handling excessive traffic. If not, it is possible that poor data rates of older Wi-Fi clients are slowing down the AP and eating up a disproportionate amount of airtime. If this is causing adverse behavior you may opt to not provide connectivity to the lower data rates on this AP to prevent these older clients from causing issues.

Top Clients


The Top Clients view shows what APs are handling the most client devices, and whether one band is more in use than the other. An over-utilized AP can limit network performance, and having too many devices on a particular band may also be undesirable.

Common Causes & Solutions:

  • Tx Power Levels: In a higher density environment, if clients are connecting to an AP but should be connecting to another nearby one, this can indicate the access point in question is broadcasting at a higher strength than other nearby APs and may benefit from decreasing the Tx power on either band. This can be accomplished through the device property panel under the Radio section. It could also indicate that the other device(s) should have the Tx power increased. Typically this is more of an issue for 5G given the limited range. If devices are connecting to 2G heavily, this can indicate the need to lower 2G Tx levels on the over-utilized AP.
  • 2.4GHz Band Over-utilized: In cases where an AP is seen to have too many clients on 2.4GHz, an administrator may opt to enable Band Steering on the AP. Band steering requires Advanced Settings to be enabled under Settings > Site. Once Advanced Settings are enabled in the UniFi Controller, band steering can be enabled by clicking on the AP with the high number of clients, opening the Properties Panel. Go to Config > Band Steering, and select “Prefer 5G”. Save and apply changes and then monitor the AP to see whether performance improves. More clients should now be seen on 5G.
  • AP Placement/Density: If one AP seems to have more clients connected to it than all the others, consider moving other APs closer, or adding another AP to ease the burden on the AP.

Top Interference


This table shows the APs that have the most RF interference. RF interference results from other wireless communications disrupting the normal wireless communication to and from the APs. Excessive interference can cause a number of adverse effects on the wireless network. Look out for sustained interference levels of double-digits and higher.

Common Causes & Solutions:

  • Poor Channel Assignment: Interference levels are specific to individual channels on each band, based on local RF environment. If you see high interference levels, do an RF Scan on the APs, then manually assign the AP to a channel on the 2.4G or 5G band that is less saturated with wireless signaling. If the network is dealing with severe interference, consider narrowing the channels (2.4GHz channels should in most cases stay at HT20 channel width, and 5GHz in noisy/high-density environments may warrant being narrowed to HT20 as well). Remember that channels must also be assigned correctly to avoid interference of other APs. Make sure to stagger channels and avoid using the same and adjacent channels on adjacent APs.
  • Tx Levels: If interference is exceptionally high in a certain location, even with devices located local to the device and assigned to the optimal channel, this may indicate that the device is broadcasting too quietly. Try tweaking the Tx power up to medium/high, or use custom levels to see if interference levels are lower with a stronger Tx level. Sometimes excessively high Tx levels in certain environments can cause self-interference. If the AP is placed on a stone/brick/metal surface, self-interference can severely impact performance. In such cases, try lowering Tx power to see if the wireless connection will perform better.

Most Active Clients


This table shows which clients are using the most bandwidth. Look out for highly utilized APs that are being over-used by a small number of clients. 

Common Causes & Solutions:

  • Network Abuse/Misuse: Abnormally high traffic from individual client devices will often point to clients that are either using the network for things that they shouldn’t like torrenting, excessive media downloads, or downloading large applications; or it could possibly also point to clients that are seeking to intentionally bring down or negatively impact the network. When this occurs in environments that include a USG, use Deep Packet Inspection (DPI) to find out what kind of traffic these clients are using and identify violations of the network’s terms of use. Problematic clients can be added to a user group in UniFi with maximum bandwidth limits. Admins also can ban these users from the wireless network altogether using the “block” button in the UI.
  • High Demand Clients: Sometimes the high bandwidth may be expected if a client device is a media server, camera or the likes. In such cases, if normal client-use is adversely affected, you may opt to confine high-demand clients to their own wireless network or dedicated access point. This can ensure that other clients have the optimal Wi-Fi experience, while still serving the most demanding clients.

Suggested article: UniFi – How to Set Traffic Bandwidth Limits


Longest Connected Clients


This view displays which clients on the network have been connected for the longest time. This is useful to identify widespread network issues, for example, if client uptime is low across the board. As well as identifying devices that should not be staying on the network for that long, for example in a coffee shop that offers complimentary Wi-Fi for current customers.


Top Memory Usage


Top Memory Usage indicates the percentage of AP hardware memory that is being used by its operations. Devices that may be dealing with abnormally high demand or may be encountering an error of some sort, may have the top memory usage. Typically high memory usage will accompany high utilization/demand; if you see abnormally high amounts of memory utilization i.e. >80%, clients may experience adverse performance.


Top CPU Usage


Top memory usage indicates the percentage of AP hardware processing resources in use by the AP at a given time. Similarly to memory usage, higher CPU usage will typically indicate the AP is more heavily in use. Abnormally high levels of CPU usage may point to a bug or an error on the AP.