IdentiFy: 2,4Ghz cllients unable to get IP

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Hello, team,

I have V2110 installation and 120 3825APs. Surprisingly, 2,4Ghz clients have stopped working. They unable to get IP. 5Ghz works fine.

What could be the reason of this?

Please, help!

Many thanks in advance,
Ilya 
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Ilya Semenov

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Posted 2 months ago

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Rob Mitchell

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Hi Ilya,

Is there anything in the controller logs? Any mention of anything major going on, any significant interference in the 2.4GHz spectrum etc?

Just to check, are the 2.4 Radios enabled still, and if there are SSIDs unique to the 2.4 spectrum are they still visible?

I've seen this the other way around (on 5GHz when local RADAR caused an issue) but not site-wide for 2.4 unless something has been changed globally.

Assuming the 2.4 radios are still on, are you using auto RF parameters or hard-coded channels and power? Has anything changed there, dropped down etc? Might be handy to look at one of the inventory reports to give you a breakdown of all APs and their 2.4 and 5GHz settings per AP for peace of mind.

Is there an authentication mechanism in the background after the controllers that might be stopping something here? If just PSK, and its an SSID unique to 2.4, has the key changed/still what you'd expect it to be? Could it be a DHCP lease issue (no IPs left, DHCP server problem etc?)

Thanks

Rob
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Umut Aydin, Escalation Support Engineer

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Hi Ilya,

did you made a upgrade recently?
What FW Version do you need?

Are all SSID's affected?

I would suggest to update to 10.41.07.

Disable 11k/MFP/fast Transistion
if enabled.

We need more details.

Regards

Umut Aydin

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Ilya Semenov

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Hi, Umut,

SW 10.41.07.0014

All SSID affected.

This is what I have in log:

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Ilya Semenov

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Hi, Umut,

are 11k/MFP/fast Transistion settings disabled? I don't know where to check MFP and Fast Transition.

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Ronald Dvorak, Embassador

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11k is disabled - I'd see it on the screenshot = Radio Management (11k) support.

The below KT article show where to find MFP/FT (Management Frame Protection / Fast Transition)

https://gtacknowledge.extremenetworks.com/articles/How_To/How-do-I-configure-MFP-Management-Frame-Pr...
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Ilya Semenov

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In my case for both SSIDs Privacy is set to None. I have redirection to external portal. So, I can't check MFP/FT status.
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Ronald Dvorak, Embassador

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Is that the same SSID that works for 2.4GHz & 5GHz and not even one client works on 2.4GHz ?

Do you use the load group feature on this SSID.
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Ilya Semenov

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Hi, Ron,

I've no idea what is it - Load Group Feature.)
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Ilya Semenov

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Ronald, I wasn't right. There is a Load Group exists. I've deleted it. Wait for a result.
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Umut Aydin, Escalation Support Engineer

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It should be ..What version do you use ?
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Ronald Dvorak, Embassador

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OK let's do that step by step....

Is that the same SSID for 5GHz and 2.4GHz ?

Per the describtion the clients on the 2.4GHz are connected to the SSID but get no IP.
- are they authenticated = if you check the client/SSID report to they all have the green lock in the first row
- who is the DHCP on that network, is it the controller or a ext DHCP
- does the communication work if you set one client with a static IP
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Ilya Semenov

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This is the same SSID.

We have external DHCP.

I'll check static IP and let you know.
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Doug Hyde, Technical Support Manager

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If you are still running into issues I would suggest contacting the GTAC for assistance: https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-contact-Extreme-Networks-Global-Tec...
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James A, Embassador

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I've been seeing this on 10.41.08, I'll have to dive into it this week. We only have a few buildings with 3825s and most devices support 5GHz, the rest of the campus is still 3710s and they work fine on 2.4GHz (you can actually walk from one building to another and the 2.4GHz only device connects as soon as you walk out the door). So it's a 3825 specific problem I think.
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James A, Embassador

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Oh, and it's not uptime related - the campus had a scheduled power outage and the problem remained afterwards.
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James A, Embassador

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I had time to file a case - 01729857. Did a remote session today, I have an AP3825 and AP3710 in the same room, on the same channel - the AP3825 sees no traffic from the client device until the SSID is enabled on the AP3710, at which point the client associates fine to the AP3710. I also did a capture from a MacBook Pro, which can see probes from the client that don't appear in the RealCapture on the AP3825. Personally my money is on the SDK upgrade for AP38xx in 10.41 (since everything was fine with 10.31) but I guess we'll see what GTAC comes back with.

Also in another area the client bounces between 4 APs, switching every minute or so with the reason code for leaving just being 1, the ever informative "Unspecified reason".
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James A, Embassador

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I found https://extremeportal.force.com/ExtrArticleDetail?n=000035073 and the suggested workaround of factory resetting the APs (they immediately re-download the config from the controller) fixed it for me.