- Microsoft relies on the "secs" value for time in seconds in DHCP Discover packets for the device has been trying to obtain a DHCP address.
- Our AP's do not increment this "secs" value, so the DHCP server never forwards the request to the secondary server when X amount of seconds is met
- The DHCP Discover packets typically should hit both servers, and the server will hash out who should respond with an offer based on a MAC address hash algorithm.
- If the ip-helper is configured on the router for only one of two+ DHCP Servers, some AP's are sending DHCP requests to to the Server may not be going to the correct server.
- According to Microsoft, even if only one of the IP helpers was configured, after a failure of DHCP for so many seconds, the windows server should have seen in the DHCP discover packet the "secs" value incrementing, and once it hits 6 seconds the server will forward the request over to the other load-balanced DHCP server.