Wireless Clients Getting Disconnected (4-Way Handshake issues)

[jacovr]

Hi all

I have a cold storage warehouse with 80.11b/g clients.

I have a WLC running  8.3.143, with.

Clients use WPA2, AES, PSK

I have clients that constantly loose connections & If i run a debug on a specific client, I get quite a lot of 4-Way-Handshake errors, (mostly failing at M3, as per the attached screenshot)

I have also included the debug, as well as sh advanced eap output.

Since this site is live, 24/7 I am unable to play around with any settings without knowing exactly what will be affected.

Any help will be appreciated

[Scott Fella]

Seem like maybe it’s a setting in your wlan configuration. Make sure you don’t have WPA & TKIP also enabled. Remove any other features on the wlan like FT and 802.11k/v/r and see if that works better. Look at the signal strength also from the client and the snr and make sure the values are good. You don’t want poor signal or else you would get a lot of retries. Do you have issue with other devices on 2.4ghz or 5ghz? That can help isolate your issue.

[jacovr]

Thanx Scott.

I do know my RF is borderline & not what it should be.  We are convincing the client to look at that.

I just need to verify that there are no other issues on the network.

On the WLAN config I only have WPA2 & AES & FT is not enabled.

There are other issues, but that can be traced back to poor signal, However these clients are affected the most.

[Scott Fella]

Can you provide more detail? What clients? Are these clients working well in other areas vs others? Can you test a client in an office area and see if the issue persists? Has this worked before? Client devices updated and the settings are correct? Can you post the show wlan

[jacovr]

Hi.

it has never been 100% stable ( i have just inherited it).

It is a cold storage warehouse and like I said, the signal is not great (some places -65 some places -72 to -76)

Unfortunately, it is Motorolla units fitted on Toyota Forklifts, so I am unable to test in a other environment.

They are experiencing these issues all over the warehouse.

I suspect it might be that these devices handle the weak signal/roamaing a bit worse than other devices, but I have to rule out all other possibilities.

Appreciate the assistance.

[Scott Fella]

Yeah, since you mentioned forklifts, you need higher density for better roaming and then you need to look at how fast these devices are going and see if the roaming is happening at each ap or not. I have done work for a cereal manufacturer that also runs scanners on their forklift and having -65 and good snr is a requirement to make these devices work well.

[jacovr]

Thanx for the response Scott !

[Scott Fella]

No problem. Fast moving vehicles tend to make thing tricky. You might also reach out to the scanner manufacturer and see what they recommend for settings.