Cisco IOS VPN Server with MS IAS User Authentication against Active Directory

This is how I have successfully configured a Cisco 2921 Integrated Services Router as a VPN server for remote users…

! [SNIP]
!
aaa new-model
!
!
aaa authentication login VPN_UserAuth group radius
aaa authentication login CLI_UserAuth local
aaa authentication login userauthen group radius
aaa authorization network VPN_GroupAuth local
!
! [SNIP]
crypto isakmp policy 1
 encr 3des
 authentication pre-share
 group 2
!
crypto isakmp client configuration group group1
 key secretp4ssw0rd
 pool group1pool
 acl 101
 save-password
crypto isakmp profile vpn1-ra
   match identity group group1
   client authentication list VPN_UserAuth
   isakmp authorization list VPN_GroupAuth
   client configuration address respond
   virtual-template 3
!
!
crypto ipsec transform-set VTI-TS esp-3des esp-sha-hmac
!
!
crypto ipsec profile test-vti1
 set transform-set VTI-TS
!
!
! [SNIP]
interface Virtual-Template3 type tunnel
 ip unnumbered GigabitEthernet0/0
 ip virtual-reassembly in
 tunnel mode ipsec ipv4
 tunnel protection ipsec profile test-vti1
!
ip local pool group1pool 172.18.1.1 172.18.1.25
!
! [SNIP]
access-list 101 permit ip 10.0.0.0 0.0.0.255 172.18.1.0 0.0.0.255
!
! [SNIP]
ip radius source-interface GigabitEthernet0/1
radius-server host 10.0.0.10 key remoteauth