We have a captive wireless clients, which are registering by the captive portal running on a NAC GW. When the client ends the registration process, I can see the resolved IP address of the client in the NAC console, but after a short time, about 10-20 seconds the IP address is gone and I get a "MAC to IP resolution Failed" in the Extended State and "Unable to resolve IP address using SNMP, NetBIOS, or DHCP" in the State Description fields. But when I check the clients report on the EWC console, the client's IP is shown.