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Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

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Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

I'm trying to help administrate an office that has a single MR53E in it providing its Wi-Fi network. The various SSIDs use WPA2, are dual band 2.4 / 5 GHz, are setup to allow 802.11g connections or later, and are configured to be in bridge mode so that our MX84 can manage the network.

 

Most of the time client devices are able to connect to this network without issue. However, every now and then a client will lose their connectivity, and when checking available Wi-Fi networks will see that our Wi-Fi network is not available. Then some minutes later it will come back and their device will reconnect. There doesn't seem to be any rhyme or reason as to which devices experience this problem: it has happened to smart phones of various makes and models as well as several different laptops. I've also found no pattern as to when it happens -- it seems to be fairly random.

 

There is also a few devices that cannot see the Wi-Fi network at all. I'm fairly certain that these devices possess the necessary capabilities to connect to our network (802.11g or newer, WPA2, etc.) and yet they can't connect.

 

While there are a lot of competing Wi-Fi networks in the area, the MR53E is set to automatically select a channel to avoid interference so I'm not sure what I can do there to improve things. In case it's a clue, whenever I turn Wi-Fi off and back on again on any of my devices, these other Wi-Fi networks are displayed almost immediately, while the ones created by our MR53E take 5-10 seconds to show up.

 

I'm quite new to all of this so I'm not sure what I should do to try and get to the bottom of this issue. Any suggestions would be much appreciated!

15 REPLIES
Head in the Cloud

Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

What switch is the MR53E connecting to? Can you check logs on that to see if the port is flapping causing the AP to reboot within a few minutes (which you won't usually see on the dashboard). If you contact support they can tell you what the uptime is on the AP in question as well.

What antenna are you using? Is it mounted in a good location?

Do you see anything in the AP event logs that stands out? Is it using a DFS channel and maybe its detecting radar and then moving away because of that?

I would open up a simple wireless scanner near the AP and just find the cleanest channel on 5GHz and hard code that in personally.

What are the data rates that you have configured on the SSIDs for the devices that do not see it at all? Those devices may only operate on 802.11b. Or if the AP is on a DFS channel, the clients may not support those channels.

Safest bet is to use UNII-1 or UNII-3 bands. (36/40/44/48, 149/153/157/161)
Nolan Herring | nolanwifi.com
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Kind of a big deal

Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

Does Wireless Health say anything interesting?

 

When you say a client can't connect - do you mean a single client can't connect but others still can (and are) connected - or that no device can connect?

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Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

@NolanHerring to answer your questions:

The MR53E is connected directly to a port on the MX84. I'll check the logs about port flapping when I have the chance, but that's probably not it since when this problem occurs it only affects one device at a time rather than all of them.

The antenna are Cisco brand dipole Antenna (MA-ANT-3-B6). I believe the AP is in a good location. All the devices report strong to very strong signal strength.

I don't believe any of the devices that can't connect are 802.11b only. Not sure about DFS -- will look into that.

I haven't had a chance to really dig into the AP logs so far, but I agree that's a good place to look for issues.

Thanks for all the suggestions so far.

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Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

@PhilipDAth

 

The issue is that a single client won't be able to connect (temporarily) but the others still can.

Wireless Health does mention some connection failures. I'm not sure how to interpret the logs, though. Most of them seem to be Association and Authentication failures. here's a small selection of them:

Authentication type='WPA-PSK auth fail' associated='false' radio='1' vap='1'
Authentication type='WPA-PSK auth fail' associated='false' radio='1' vap='3'
Association type='Association attempts' num='3' associated='false' radio='1' vap='3'
Authentication type='WPA-PSK auth fail' associated='false' radio='1' vap='2'
Association type='Association attempts' num='4' associated='false' radio='1' vap='2'

Kind of a big deal

Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

The fact that only individual clients at a time are being affected is a big one.

 

The log below "PA-PSK auth fail" indicates that the RADIUS server is refusing to allowing the client to connect.

 

You need to check the logs on your RADIUS server to determine why.

If you have a non-standard password lockout policy what can sometimes happen is when a user changes their AD password but doesn't change it on their device it triggers the account to get locked for a short period of time, resulting in the RADIUS server refusing the connection.

 

The RADIUS server log will hold the key to the issue.

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Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

@PhilipDAth I don't believe we're using a RADIUS server or WPA2 Enterprise. We've just got the SSIDs association requirements set to "Pre-shared key with WPA2".

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Kind of a big deal

Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

Interesting.  So the question is why is the auth failure happening.

 

What firmware version are you running on the AP?

 

You are not running any other brands of AP as well at the same site using the same SSID?

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Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

On the MR53E it says it's firmware is up-to-date, version MR 25.13.

 

The MX84 has a firmware update available that I haven't installed yet.

 

There are no other APs running in this office. However we used to have a consumer grade AP (not sure what model) that was providing a Wi-Fi network using the same SSID as the MR53E is now. I've since created a few other SSIDs on the MR53E just in case that was causing issues, but on any device that experiences this problem, all of the SSIDs provided by the MR53E disappear, not just the one that used to come from the older AP.

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Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

@PhilipDAth Another bit of info: the two devices that couldn't connect at all were a cheap $40 Android prepaid phone and an old iPod Touch 3. When I created an SSID that used either no encryption or WEP they were both able to connect to that, so I'm guessing that they don't use a modern enough version of WPA2 to be able to connect to our other SSIDs. Does that sound right?

 

(For those that might be concerned about the security of my wireless network, don't worry, I'm not going to keep an unencrypted or WEP SSID up. That was just for testing.)

Kind of a big deal

Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

Perhaps try enabling WPA1 as well.

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Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

After a few days of no incidents, today we had several devices suddenly become unable to see any of our SSIDs. After about half an hour one of the devices started to be able to see one of the SSIDs again, but the others still couldn't. Someone at the office rebooted both the MR53E and the MX84 and it cleared up the problem.

 

I'm starting to get quite concerned about this. So far this equipment is working worse than the consumer grade wireless router we were using previously! Does anyone have any other ideas as to what could be going wrong?

 

While this was happening, there were more "Failed connections" entries in the wireless health page for the MR53E:

 

Thu Jan 10, 2019, 16:28:33  client1          Wireless Access Point   SSID1   Authentication  type='WPA-PSK auth fail' associated='false' radio='1' vap='0'
Thu Jan 10, 2019, 16:21:03  desktop-client2  Wireless Access Point   SSID2   Authentication  type='WPA-PSK auth fail' associated='false' radio='1' vap='2'
Thu Jan 10, 2019, 16:20:23  desktop-client3  Wireless Access Point   SSID1   Authentication  type='WPA-PSK auth fail' associated='false' radio='1' vap='0'
Thu Jan 10, 2019, 16:20:13  android-client4  Wireless Access Point   SSID1   Authentication  type='WPA-PSK auth fail' associated='false' radio='1' vap='0'
Thu Jan 10, 2019, 16:16:43  client5          Wireless Access Point   SSID1   Authentication  type='WPA-PSK auth fail' associated='false' radio='1' vap='0'
Thu Jan 10, 2019, 16:11:23  desktop-client6  Wireless Access Point   SSID1   Authentication  type='WPA-PSK auth fail' associated='false' radio='1' vap='0'
Thu Jan 10, 2019, 09:29:42  client5          Wireless Access Point   SSID1   Association     type='Association attempts' num='3' associated='true' radio='1' vap='0'
Thu Jan 10, 2019, 09:29:22  client5          Wireless Access Point   SSID1   Authentication  type='WPA-PSK auth fail' associated='false' radio='1' vap='0'
Thu Jan 10, 2019, 09:28:52  client5          Wireless Access Point   SSID1   Authentication  type='WPA-PSK auth fail' associated='false' radio='1' vap='0'

(I've changed the device names, MAC addresses, and SSID names for privacy reasons.)

 

I'm afraid I do not understand what those error entries mean, aside from there being some kind of authentication issue.

 

Is there anything else we can do to address this?

Head in the Cloud

Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

Can you show a screenshot of the event log for the AP in question. Its possible the radio is no longer working. Also show a screenshot of the RF tab, that would show you if clients just 'dropped' for that window of time.
Nolan Herring | nolanwifi.com
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Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

@NolanHerring I've attached two screen shots. The problem was reported to me around 16:00 on January 10, and the screen shot I took of the event log is from around that time.

 

Screen Shot 2019-01-11 at 1.28.28 AM.png

 

Screen Shot 2019-01-11 at 1.31.07 AM.png

 

Head in the Cloud

Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

So I was looking for a very obvious symptom that I'm quite familiar with where the 5GHz radio simply stops working. I don't see that happening. Plenty of clients still actively using the AP, so I can't help but want to lean towards a client related issue in this case.
Nolan Herring | nolanwifi.com
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Re: Clients sporadically cannot connect to Wi-Fi networks created by MR53E.

I've been looking for some kind of client-related explanation too, but as I've mentioned there's no connection or commonality among the clients this happens to. These are all devices that have no trouble connecting to other wi-fi networks.

I'm starting to think our AP is defective. I'll probably contact Cisco support directly at some point in the not too distant future.