Radius configuration trick to allow "CLID-like" filtering on ACS for l2tp/pptp

Here is "trcik" to allow l2tp/pptp client access filtering based on their IP-address for ACS 5.X
1) configure NAS with "vpdn aaa attribute nas-ip-address vpdn-tunnel-client"
This command will allow IOS to send client ip address in attribute 4 like this output from debug:
RADIUS:  NAS-IP-Address      [4]   6  1.2.3.4
2) Use "compound condition"  in ACS Access Policies - Authorization rules to match based on this attribute.
Tested on 15.1(4)M6 IOS for 7200 series router.