We have a vWLC controller running 8.5.160. All (11) APs are connecting to the vWLC in flexconnect mode and processing local switching for the clients at each site. We are funneling the guest clients directly out to our local comcast networks at each site, where the local comcast modem is allocating DHCP and providing the internet access. The APs register just fine on the controller, failover works great, the clients can connect and grab an IP address from DHCP, but the clients at our remote locations do not automatically pull up the splash page, so they cannot authenticate, therefore they cannot get to the internet.
The Virtual Interface IP is: 192.0.2.1 and we have upgraded the OS twice recently to see if that resolves the issue.
We have the vWLC onsite at our "MAIN" office and everything works fine there. We have the "GUEST" SSID up and running at each site just fine. The AP CAPWAP is registering as the APs respond to all controller commands. The guest clients can type in the PSK for the SSID and connect to the WiFi, but they are not getting redirected to the splash page as they are at the "MAIN" office. At the remote sites we can have the guest clients go to the Virtual Interface in their URL and they can get the splash page that way. Something seems to be missing, or the controller is just not working like it should be.
I am hoping that someone here can hopefully help or at least rule out some other possible configuration mismatches. I already have a case open with Cisco TAC and they are trying to replicate the issue in their environment, but we have had this case open for months and they have not been able to shed any light on the issue. Please let me know if any additional information is needed to assist. Any help is appreciated at this point.