We are having trouble with guests completing the captive portal registration on the NAC. This is apparently a MAC-to-IP resolution issue between the EWC and the NAC. The subnet for the captive portal is 10.200.x.x and the DHCP is handled by the EWC's onboard DHCP for the topology.
I doing something wrong because the NAC is not resolving these addresses therfor they connot complete registration. The information from the switches resolves perfectly but not from this "guest" subnet. I am sure there is a check box somewhere I am missing, any help?
As you mentioned that NAC portal is not in same subnet, I think the ip-helper or bootp relay configuration would be need in core switch so that the NAC could get the DHCP packets for MAC-to-IP resolution.