Wired 802.1x auth - Getting the IP address of the authed machine

I have a wired 802.1x auth setup on cisco gear. I would like to record the IP address of machines that connect and are authorized. Is this possible? I currently see NAS-IP-Address and Client-IP-Address as the IP of the switch. The Calling-Station-Id is the correct mac address of the authorized machine. The machines that are connecting to be authed are allocated their address using dhcp. Cheers Paul