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Re: Intermittent connectivity loss with UAP-AC-PRO

[ Edited ]

RJTPlomp wrote:

So my experience now is, Apple mobile devices in the house?: DTIM must be set to 3.

@UBNT-jeff - this really needs to be called out in the quickstart guide or something.

 

Or maybe a radio button in the WLAN setup that says "Optimize for older Android Devices or Optimize for iOS Devices" since iOS devices REALLY don't like a DTIM other than 3.  

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Re: Intermittent connectivity loss with UAP-AC-PRO

@EricE Sure, we will update this guide: https://help.ubnt.com/hc/en-us/articles/221029967-UniFi-Debugging-Intermittent-Connectivity-Issues-o...
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Having connectivity issues? See: https://help.ubnt.com/hc/en-us/articles/221029967-UniFi-Debugging-Intermittent-Connectivity-Issues-on-your-UAP
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Re: Intermittent connectivity loss with UAP-AC-PRO


UBNT-jeff wrote:
@EricE Sure, we will update this guide: https://help.ubnt.com/hc/en-us/articles/221029967-UniFi-Debugging-Intermittent-Connectivity-Issues-o...

While that's good, I also think this needs to be in the basic controller documentation as well. 


Call me crazy, but I would think recent iOS and Android devices are far more common than older Android devices.

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Re: Intermittent connectivity loss with UAP-AC-PRO

I agree, IOS compatiblilty should be a feature not a repair
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Re: Intermittent connectivity loss with UAP-AC-PRO

@rocketllc We actually use DTIM 1 on most of our test networks, and have not been able to replicate this issue with our iOS devices (test and personal) on demand. We would love to know how to replicate it, though!
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Re: Intermittent connectivity loss with UAP-AC-PRO


UBNT-jeff wrote:
@rocketllc We actually use DTIM 1 on most of our test networks, and have not been able to replicate this issue with our iOS devices (test and personal) on demand. We would love to know how to replicate it, though!

Pretty easy, hook up an edgerouter to two UAP-AC-Pros, configure iOS device to the SSID, roam between the two access points several times.  Eventually you'll get an APIPA address on that iOS device.

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Re: Intermittent connectivity loss with UAP-AC-PRO

@ricoviq We've tried that many times; it does not happen for us Man Happy
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Re: Intermittent connectivity loss with UAP-AC-PRO

I had a very similar problem.

Are you running any video streaming services on your network? Have you evaluated your traffic (eg Wireshark)? Do you have IGMP snooping on?
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Re: Intermittent connectivity loss with UAP-AC-PRO


UBNT-jeff wrote:
@ricoviq We've tried that many times; it does not happen for us Man Happy

The config I used specifically for this to happen,

 

1xEdgerouter POE (the 5 port one) - Only basic configuration using the wizards to set up WAN connection and the default 2 VLANs, only other config I really did on the edgerouter was the POE settings for the two ports for the UAP-AC-Pros, and a couple of port forwarding rules for things like HTTPS and SMTP.

 

2xUAP-AC-Pros - On these I configured a single SSID for 2/5 Ghz, and auto everything else really.  WPA2 Personal, single site.

 

With this config I started noticing the APIPA issues, at that point is where I started messing with all the additional firmwares in this thread, minimum RSSI, transmit power, none of which worked.  I might try the latest setting mentioned here.  (changing that one setting from 1 to 3).

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Re: Intermittent connectivity loss with UAP-AC-PRO

Hi,

 

Well I use Plex in the house yes. That streamss from a server to rasp-pi clients, but that's all wired.

 

The things that are wireless are iPhones, iPads and my Sonos speakers.

 

I haven't inspected any traffic with WireShark or anything. IGMP snooping is off I think, not even sure what that is or what it does. I'm not a network pro, just trying to fix what I find to be broken.

 

ROland

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Re: Intermittent connectivity loss with UAP-AC-PRO

From what I understand about DTIM is that it's a traffic regulating message, send right after the general beacon message  (sends SSID and capabilties of network, etc.) that is the backbone structure of the wireless signal all together. DTIM is send every xth time after the broadcast message. Where x is the DTIM setting. So beacon message is send every 102,4 millisecond I read, so DTIM message is send every 307,2 millisecond then.

 

DTIM message tells 'sleeping' (for powersave purposes) client that the IP is holding buffered information that needs to be delivered.

 

That's also all I know to be honest and all I understand from what I read. 

 

But with that knowledge I can't still figure why or how changing the DTIM value will lead to a client losing it's IP-adress and that then gets replaced by an APIPA. If someone with more knowldge on this can explain how that is related, maybe that will help to understand how this may go wrong. If this is at all related!

 

I mean I've tried a lot of things the last year, and sometimes it seem to help, but than problem came back. So now, cause I don't understand how this seems to solve the problem, I'm still not entirely sure this is THE fix.

 

Is there someone on this forum that can explain how this all interacts? And how this can go wrong?

 

I'm most certainly willing to test things. If it helps anyone.

 

For Ubiquiti:

I fully agree with others that if this is a setup-choice to make, it should be upront in the setup-process. Not somewhere in a forum, 10.000 miles deep.

 

I love the way you guys develop things, I really do. But the way things are supported needs some kind of structure I believe. I have been in contact with a lot of Ubiquiti people in chats the past year, from your support organization. No one, and I mean no one will confirm that there are issues with Apple iDevices. Let alone that they point out in those chats (sometimes hours long), or TeamViewer take-over support sessions, that DTIM should be set to 3. I get the impression that really no one knows this. Where all the time my support question was that I lost connection on Apple devices. I think the guys that do know that this is an issue, or can be a set-up issue, should tell the guys and girls that support customers get this on their priority list of questiosn to ask as well.

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Re: Intermittent connectivity loss with UAP-AC-PRO

[ Edited ]

All firmware devs like @UBNT-jeff can do is point out how it’s supposed to work - sadly every device vendor has their own quirks in their wifi device driver implementations (the great things about standards - so many to choose from and so many ways to interpret them) so often the only way to discover there are issues is to experience them Man Sad

 

Then hope the UBNT guys can reproduce the problem.  Once you get it reproduced then you can start to work on a fix.  

 

Until then - we just tend to go in circles taking blind stabs with tidbits of knowledge like “iOS devices tend to work best with DTIM of 3” and such.  

 

Otherwise known as the “magic incantations”.  Which is where the high priests of the glass house (glass house = datacenter) mythos from the earliest days of computing spring from and all that.  


Everything new is old again after all Man Wink

When you receive a solution to your question/issue, don't forget to mark your thread as solved and to give kudo's to the people who have helped you out!

Having wifi problems? Take a look here first: https://help.ubnt.com/hc/en-us/articles/221029967-UniFi-Debugging-Intermittent-Connectivity-Issues-on-your-UAP
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Re: Intermittent connectivity loss with UAP-AC-PRO

I think the bigger problem is this isn't a Ubiquiti problem. I've seen similar sounding posts on several other wireless device maker sites. Most of the time the threads are brushed off as a user problem. 

 

But the recurring theme is IOS devices have wireless problems. Have for years, this isn't new. They do something differently than EVERYONE else and we all run around like there's something wrong with the Ubiquiti devies or the Asus routers or the TPLink routers or even Cisco enterprise wireless deployments. 

 

We make changes, we update firmware, we change to old firmware, there's obsure settings being changed that claim to fix it for sure, yet the problem continues across the many different device makers. The only common problem is Apple devices.

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Re: Intermittent connectivity loss with UAP-AC-PRO

I get you’re not a network pro and neither am I. However, we’re both wading into the enterprise tech realm here and we need to educate ourselves.

Plex appears to use UDP. Those packets clog up an AP and affect connected devices. You may have what is referred to as a ‘network storm.’ Turn on IGMP snooping or move UPD traffic off APs physically or virtually.

I have done what you have. Downloading firmware, trying different settings. At the end of the day, it was poor network configuration that caused the problem. Happy Hunting!
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Re: Intermittent connectivity loss with UAP-AC-PRO


dab wrote:

Plex appears to use UDP. Those packets clog up an AP and affect connected devices. You may have what is referred to as a ‘network storm.’ Turn on IGMP snooping or move UPD traffic off APs physically or virtually.


Plex does use UDP for data-transport. And there is a setting in the controller where I can turn on IGMP snooping, but I don't think that setting has any meaning when I don't have the Unifi-switches (which I don't). IGMP has to be set on a switch I believe?

 

BTW I am thinking of getting two Unifi switches with POE. Cause now that everythink works as a dream -after this struggle-, I think I want to get rid of all the POE-injectors in the house. And on top of that I feel my corrnet low end managed switches are barely up to the job of switching the amount of data that goes over them at times.

 

And to update everyone another few days later on changing the DTIM to 3, I haven't experienced anymore 'disconnects' (fallbacks to APIPA on iDevices).

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Re: Intermittent connectivity loss with UAP-AC-PRO

@RJTPlomp FWIW we have actually talked with Apple devs regarding how they handle DTIM, and they would rather save battery power than ensure 100% packet success, so I can understand why we see strange things when the DTIM is set to 1. Their whole WiFi ecosystem is based around a DTIM value of 3, from what I can tell...
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Re: Intermittent connectivity loss with UAP-AC-PRO


UBNT-jeff wrote:
@RJTPlomp FWIW we have actually talked with Apple devs regarding how they handle DTIM, and they would rather save battery power than ensure 100% packet success, so I can understand why we see strange things when the DTIM is set to 1. Their whole WiFi ecosystem is based around a DTIM value of 3, from what I can tell...

Yes seems so. They do things differently, that is, less flexible and how they think it works best. Doesn't matter if that is interactive with the rest of the world, actually rather not, that helkps them sell their own stuff.

 

Thx. 

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Re: Intermittent connectivity loss with UAP-AC-PRO


UBNT-jeff wrote:
@rocketllc We actually use DTIM 1 on most of our test networks, and have not been able to replicate this issue with our iOS devices (test and personal) on demand. We would love to know how to replicate it, though!

I can't help with replicating but after happening across this thread, I used SSH to set DTIM on my two AC-PROs to 4 which instantly solved the loss of connection problems on my iPhone 7 with iOS 11.  Complete night and day difference.  I also discovered that recent controller versions now have the ability to set DTIM.  I am running controller 5.5.2.4.  Using that I have set DTIM for the site on both 2.4 and 5 GHz networks to 3, as seems to be the most commonly recommended setting for iOS devices.

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