Wireless Clients disconnect, not able to reconnect

[Banana Pancakes]

I have a WLC 5508 in my datacenter, and 1142s configured with FlexConnect at a remote site.

Two issues:

Some APs 'die' from time to time where I cannot ping them anymore and they do not service any clients. I can reset them from the WLC after which they work again.

I have some clients in the building (same area) who lose connectivity from time to time and are unable to reconnect to the wireless. I am seeing errors that the gateway cannot be found or there is not a valid IP. restarting the AP closest to the clients fixes the issue. I have replaced the AP and connected to a different port on the switch.

What is going on?

[Kayle Miller]

Sebastian,

     Can you provide a bit more detail?

Are the AP's in FlexConnect/H-REAP Mode?

Are they setup to support VLAN's?

Do they have a Native VLAN?

Are you using Pre-shared Key or 802.1x Authentication?

When you have an AP that has this issue what is the uptime of the AP versus the Associated Time?

What code version are you running on the 5508?

Thanks

[Banana Pancakes]

The APs are in FlexConnect Mode.

On the WLC I was running 7.2.111 but am now running 7.4.100 (I continue to have the same issues as before).

port config at remote site for the 1142s is

switchport trunk encapsulation dot1q

switchport trunk native vlan 220

switchport trunk allowed vlan 220, 222, 224,226,228,230

switchport mode trunk

switchport nonegotiate

the port config for WLC is

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 100, 120, 122, 124, 126, 128, 130

switchport mode trunk

VLAN 100 is the management network

We are using a RADIUS server for 802.1x authentication on the faculy and student networks as well as the byod network.

[Kayle Miller]

Sebastian,

     Have you gone under each AP and enabled the VLAN Support, and then specified the VLAN for each WLAN SSID that you have configured for FlexConnect mode?

Hope this helps!

[Banana Pancakes]

Yes I have done that, unfortunately that is not the soluation. Remember that clients will connect sucessfully. Then randomly they will disconnect and not be able to reconnect with the message gateway could not be found or invalid ip .

One thing i just noticed looking at the logs is this error mesasge related to clients to cannot reconnect

*apfMsConnTask_3: Jan 28 10:06:58.833: #LWAPP-3-INVALID_AID2: spam_api.c:1357 Association identifier 6 for client -lists MAC adddress here- is already in use by -lists other MAC address here-

I have also found this discussion which seems to address the same issue:

https://supportforums.cisco.com/thread/2191463

[grabonlee]

Your problem is your switch port configuration at the WLC. You have blocked vlans coming from the remote site. Remember that the APs will still need to reach the WLC even if you are running flexconnect.

Allow the vlans from the remote site and see what happens.

[Kayle Miller]

That is a good catch and correct, it could very well be that.