Hi,
Currently, on the supplicant switch, you have to configure a port as a supplicant port. it's the link between your authenticator switch and your supplicant switch which allows 802.1x through cascaded switchs.
The command lines for your hp supplicant switch are :
"aaa port-access supplicant <PORT_NUM>"
"aaa port-access supplicant <SAME num=""> identity <LOGIN switch=""> secret"
you will be prompted to enter a password
you can use radius with AD. You have to create a user (your switch supplicant) with login: <LOGIN switch=""> and password: <SWITCH secret="">.
hope i helped you but jeff will explain it better than me.
regards
manu</SWITCH></LOGIN></LOGIN></SAME></PORT_NUM>