Lwapp discovery request rejected

[Kizowa Joao]

I´m trying to connect a new AP to the controller but it not working.

Error: Discovery request decoding with subnet broadcast and wrong AP IP address.

AP Model: AIR-CAP3502P-E-K9

Controller Model:  5508 

Software Version: 8.5.135.0

[Leo Laohoo]

Post the complete output to the following commands: 1. WLC: sh sysinfo; 2. WLC: sh time; 3. AP: sh version; and 4. AP: sh ip interface brief

[Kizowa Joao]

Manufacturer Name.............................. Cisco Systems Inc.
Product Name..................................... Cisco Controller
Product Version.................................. 8.5.135.0
Bootloader Version............................... 1.0.20
Field Recovery Image Version..................... 7.6.95.16
Firmware Version................................. FPGA 1.7, Env 1.8, USB console 2.2
OUI File Last Update Time........................ Sun Sep 07 10:44:07 IST 2014

Time............................................. Thu Apr 11 12:08:13 2019

Timezone delta................................... 0:0
Timezone location................................ (GMT) London, Lisbon, Dublin, Edinburgh

Access Point version: 7.5.102.0

[Leo Laohoo]

Post the complete output otherwise raise a TAC Case.  

[Kizowa Joao]

I can not get  sh ip interface brief command on the AP

[Leo Laohoo]

Post the COMPLETE OUTPUT to the following commands: 1. WLC: sh sysinfo; 2. WLC: sh time; and 3. Switch: sh cdp neigh detail

[Kizowa Joao]

Switch sh cdp neigh output

BXXXX-9thFL-XX-A-AP01
                 Gig 10/16 ______147_____R T___AIR-CAP35 Gig 0.1

[Leo Laohoo · Accepted solution]

Please raise a TAC Case because I will not be providing any more assistance since you're not forthcoming with important information.   

[Georg Pauwen]

Hello,

below is an excerpt from the linked document. Check the VLAN/Trunk config...

Problem 10: Controller receives AP discovery message on wrong VLAN (you see the discovery message debug, but not response)
You see this message in the debug lwapp events enable command output:

Received a Discovery Request with subnet broadcast with wrong AP IP address (A.B.C.D)!
This message means that the controller received a discovery request via a broadcast IP address that has a source IP address which is not in any configured subnets on the controller. This also means the controller is dropping the packet.

The problem is that the AP is not sending the discovery request to the management IP address. The controller is reporting a broadcast discovery request from a VLAN that is not configured on the controller. This typically occurs when the customer trunks allowed VLANs instead of restricting them to wireless VLANs.

Complete these steps in order to resolve this problem:

1. If the controller is on another subnet, the APs must be primed for the controller IP address, or the APs must receive the controllers IP address using any one of the discovery methods.

2. The switch is configured to allow some VLANs that are not on the controller. Restrict the allowed VLANs on the trunks.

https://www.cisco.com/c/en/us/support/docs/wireless/5500-series-wireless-controllers/119286-lap-notjoin-wlc-tshoot.html

[Kizowa Joao]

Hi Georg

You're right this should be the root cause. I´ll check the configuration on the interface. The most trick in this case is that the AP model AIR-CAP3702I-E-K9 work without any issue.

[Georg Pauwen]

Hello,

I checked for bugs or any other information related to your specific model but could not find anything, so the troubleshooting is probably valid regardless of the model.

Curious to know if there is an issue with your interface configuration...