Unifi TX Retries

I have a modest homelab with a managed network, running unifi gear… I know enough to be dangerous, but not enough to diagnose all of my issues.

I have had seemingly random drops in facetime calls on my iPhone, but nothing like “oh wow this must be broken”… but looking through the GUI I am seeing the bellow, these three devices are all apple devices, and all on my 5 GHz SSID. I do have other apple devices on my 2.4 GHz SSID and they have 0 retries…

These three devices below are the only ones on the 5 GHz band (my phone, my ipad, and my macbook). The two apple devices on the 2.4 SSID are my work iPhone and iPad (IoT SSID, which is only 2.4 GHz).

I only have 1 AP, a U6-Lite. Router is pfsense. I don’t see any internet issues personally, and pfsense reports 0 loss (not that I think this is internet/WAN related, it certainly seems like 5 GHz/SSID related since its only happening to the devices on the 5 GHz band…).

Any idea what is causing this, is it a concern, and what should I try to fix it if it is something worth fixing?

Would be good to know what channel you are on and any other WiFi signals in the 5GHz band possibly causing interference. WiFi Scanner app for your MacBook would be a good tool. Also, do you know how to get a screen capture of your system configuration? I believe its only in the legacy interface.

I could download that app, but I easily can just show what unifi is showing as currently on the spectrum, if this is helpful…

It looks like most of the band is pretty empty assuming I am reading this correctly - I also did set it to auto channel switch every night yesterday, so I am not sure what channel it was on prior to yesterday.

Also I see this, seems to at least show what channels I am currently on.

If you do want anything more specific let me know… I am not sure where in the legacy interface settings would be, I started using unifi as the new GUI was released (it sucked to be fair at first… couldn’t even set up vlans).

Those numbers look pretty solid to me. 16.6% retries is nothing. They will never be 0%

Oh really? The only reason I found it interesting is due to the fact all of the devices on 2.4 GHz do seem to be at 0% as seen below. This is a screenshot of all of my devices, top 3 are the 5 GHz connected devices.

Looks like you have the power on both 2.4 and 5 GHz set to high. I would set 2.4 to medium to start and maybe to low to encourage more traffic to the 5GHz band. If you scroll down in the power settings you will see custom settings…this gives greater granularity and you can set power specifically. For now, 5GHz on high, 2.4 to medium. Also, channel 11 looks better for 2.4…keep width at 20. For 5GHz, move channel width to 80 for greater throughput and keep at channel 38.

In WiFi settings, make sure WPA is set 2 only. Apple products will appreciate it…lots of issues with WPA 3. Set DTIM on 2.4 to 1 and for 5GHz 3. No band steering, UAPSD set to on, No fast roaming, PMF disabled. To minimize retries, use the minimum data rate controls…2.4GHz to 6 and for 5GHz to 12; and never allow unifi to auto-optimize settings. If you have any IOT devices on 2.4GHZ that have infrequent transmissions then you hight have to lower 2.4GHz data rate control lower than 6.

It’s all about tuning the WiFi

Thanks for this info!

My 2.4 GHz band is mostly for IoT stuff, so should I go ahead and lower the data rate control to, say… 4? 4 isn’t a thing come to find out, I set it to 2… is there any reason this would be bad for signal strength or bandwidth? I guess I am not entirely sure what this data rate control does exactly.

I more or less set all of my “less important” devices to 2.4 GHz since for the most part IoT stuff is only 2.4 GHz, thus my IoT SSID only gets 2.4 GHz, and my main LAN is set to only 5 GHz (iPhone, laptop, etc).

I will make those changes, just unsure if I should lower the 2.4 GHz data rate knowing its almost exclusively for IoT devices (and a work iPhone and laptop I don’t need sniffing around my network).

I also didn’t realize not all of the SSID’s were being shown on the graph. I enabled showing all at once, and this is the actual spectrum graph, but seemingly the recommendations from before still hold, at least to my eye. Thoughts?

I wouldn’t lower data connection rate until you see if there is a problem. Data connection rate controls “disconnects” devices that have too low of a data connection rate…such as devices that are far away with poor connections…these are major causes of retries. Symptom will be IOT doesn’t connect. If a device is offline, just keep lowering 2.4GHz minimum data connection rate.

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Agree with the statements made about 2.4 GHz, as this is essentially a legacy tech and should not be relied on for anything more then IoT. Also as you are supporting Apple devices, check into the mDNS (multicast DNS) config on your network for support of Apple Bonjour services as that has caused issues in the past on client networks with more than one client Apple device active.

What would I need to check for mDNS? Would that be in unifi settings, or pfsense at the router level? Basically, what exactly am I looking for?

I should add, I do have avahi running on pfsense, not sure if that is what you would be referring to?

Under network settings just make sure mDNS is checked

If you have VLAN only networks mDNS settings will look like this:

Screen Shot 2022-08-28 at 3.24.30 PM

Wondering if I have something set up wrong…

I have multiple vlans setup, the main “top level” one is just named management, its what pfsense UI, proxmox webUI, etc live on. But on this page, I only seem to see the option to check it on for that management network… should it be showing all of the configured vlans here? If it should be like it seems like yours is, why wouldn’t it be?

If I click on my management network in the networks setting up at the top (where it lists all of the networks), I get to this page where it does have an image similar to what you posted second. I guess I am not sure why mine looks different, and has me wondering if something is set up incorrectly.

I have multiple vlans set up in pfsense, I trunk in the management subnet to my AP, then I have multiple vlan only networks set up with different SSID’s.

No, you are good. If you have VLAN only networks those are the screens. You should probably check the Multicast DNS checkbox so multicast packets are forwarded within Unifi.

Ok, maybe a better question… should I have vlan only networks? How does your AP have multiple networks coming in, do their higher end devices have multiple LAN ports and thus you have multiple physical networks coming into it?

And what does multicast do exactly? I have had it off this entire time and things seem fine… I can chromecast fine, control all my devices, (granted, my phone is on private lan, and Avahi in pfsense is broadcasting it across the subnets to IoT devices).

I am trying to actually learn a thing or two here as well. I greatly appreciate the help.

Start at this point (8:35) on the video link below:

Hope this helps.

Hmm, I guess I am a little confused. If I have mDNS off, how is chromecast and such actually working as expected?

FYI, I also use Pfsense as a firewall/router. With Pfsense as the firewall there is no need for the “corporte” network in Unifi. When I setup my Pfsense/Unifi network, there was no real Vlan only network…only the corporate. That is why I have some of the corporate networks. My camera network is Vlan only and behaves the same as the corporate networks since I’m using Pfsense as the firewall. If I had a Unifi router, you use the “corporate network” network.

The hardware I’m using for Pfsense is a 6-port Protectli but I only use 1 port for WAN and another for LAN. All of my VLANs ride over the one physical LAN network. You can of course use separate ports but this is simpler for me.

Multicast is defined in networking as a protocol when you can broadcast one-many or many-many. Lots of devices use multicast communications without you knowing about it. Chromecast is one example, most printers today use multicast to see if the printer is attached to the network and what protocols it suppiorts, Sonos speakers are another example, Apple Airprint…lots of multicast is in use today. You have Avahi running on Pfsense…I assume that is to allow multicast traffic between VLANs…that is how your Chromecast works. So why is this working without mDNS checked in Unifi? Simply because what Unifi filters is not the addresses used by the chromecast or it is not being filtered in the specific Unifi switch. There are an array of addresses used by multicast traffic and there is lots of variability in how multicast can be implemented so you can leave things as is or if you have an issue try checking the mDNS box in Unifi. Totally up to you and no harm either way.

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This was a great description of how this works, and makes a good bit of sense. Thanks for that!

I am in a similar situation, I have a 4 port NIC passed through proxmox to my pfsense VM, and I only use 2 ports; 1 WAN and 1 LAN, everything else runs as a VLAN over the single physical interface/wire.

It would appear as though my Wifi experience on my iPhone has gotten worse. I am not entirely sure if that was iOS 16 related or it is due to some of these settings changes (I was on the beta for about a month prior to launch).

Sometimes my phone will drop from Wifi, and when I go into settings, the SSID which I should be connected to won’t be listed as an option to connect to. If I wait 20-30 seconds, it will return to the list and typically will auto connect.

I don’t seem to see this issue with my MacBook, and these are the only two devices I really interact with enough on that SSID to be able to tell if there was an issue.

Any ideas? I am getting an iPhone 14 today to replace my Xs, maybe it having Wifi 6 will help? Maybe that is just wishful thinking. (And no, I didn’t buy a new phone because of this issue)