We have a used set of two Cisco WLC 4402 controllers. They have separate IP addresses on two different class C subnets. I have two different dhcp scopes that handle the ip addresses for each controller to hand out to the APs. These scopes live on different vlans to keep the proper dhcp scope with the proper controller. I know I am doing something wrong because I managed to get some AP 1142 gig APs. I am trying to get them to join one controller. I have the vlan untagged for AP manager and the AP gets the correct address from the correct scope on the switchport I am using. I know this because I can ping from the AP to the correct controller. However after the AP get its IP address I keep getting these errors
*May 14 19:10:46.049: %CAPWAP-5-CHANGED: CAPWAP changed state to DISCOVERY
*May 14 19:10:56.000: %CAPWAP-5-DTLSREQSEND: DTLS connection request sent peer_ip: 192.168.17.2 peer_port: 5246
*May 14 19:11:10.001: DTLS_CLIENT_ERROR: ../dtls/dtls_connection_db.c:1924 Max retransmission count reached!
*May 14 19:11:10.001: %DTLS-3-HANDSHAKE_RETRANSMIT: Max retransmit count for 192.168.17.2 is reached.
The 192.168.17.2 address is from the AP manager interface of the other controller. I need it to see the other AP manager interface. Is there a way I can force this? In my DNS I have capwap and lwapp set to the same ip addresses. It was working fine because I was controlling which AP manager IP address was advertised with the untagged vlan on the destination switchport. Strange thing is the vlan for the other AP manager is not even present on this switch.
You can try below command on your AP & see
capwap ap controller ip address <wlc-mgt-addr>
What software version is running on those old 4402 ?
During the discovery phase of AP-WLC association process, an AP doesn't only discover via DHCP.
It can also acquire WLC information over-the-air from neighboring APs.
The other AP that keeps on choosing the other WLC may have already stored it's previous connection with that controller on it's memory.
You can do a factory reset on that AP or hardcode the configuration of the Primary Controller.