User authentication in Cisco ACS by adding external RADIUS database

Question

Hi,
I would like to configure the below setup:
End user client (Cisco Any connect/VPN client) -> ASA 5500 (AAA client) -> ACS server -> External RADIUS database.
Here ACS server would send the authentication requests to External RADIUS server.So, i have added the external user database (RADIUS token server) in
ACS under External databases.I have added AAA client in Network configuration (selected authenticate using RADIUS(VPN 3000/ASA/PIX 7.0) from the drop down.
Here how do i make ASA recognize that it has to send the request to ACS server. Normally when you use ACS as RADIUS server you can add an AAA server in ASA and test it.But here we are using an external RADIUS server which has been configured in ACS, so how do i make ASA to send the requests to ACS server?
Any help on this would be really grateful to me.
Thanks and Regards,
Rahul.

Answer 1

Thanks Ajay,
As you said nothing needs to be done on ASA side, if we are using an external user database for authentication.
Im a newbie to ACS and this is the first time i'm trying to perform a two factor authenticaton in Cisco ACS using external user database.
By two factor authentication i mean, username + password serves as first factor (validated by RADIUS server), username + security code (validated by RADIUS server) serves as second factor.So, during user authentication i enter only username in username field and in "password" field i enter both "password + security code". Our RADIUS server has already been configured with AD as user store, so we dont have to specify AD details in ACS. I have done the following in ACS to perform this two factor authentication.
-> In external user databases, i have added a external RADIUS token server.
-> In unknown user policy , i have added the external data base that i configured in ACS into the selected databases list.
-> under network configuration, i have added the Cisco ASA as AAA client (authenticate using RADIUS (Cisco VPN 3000/ASA/PIX 7.x+)).
Just to check whether user authentication is successful, i launched the ACS webVPN using https://IP:2002, it asked me to enter username and password. So, i entered username and in password field i entered "password + security code". But, the page throws an error saying "login failed...Try again".I cant find any logs in external RADIUS server.
Here is what i found in "Failed attempts" logs under Reports and activities.
Date,Time,Message-Type,User-Name,Group-Name,Caller-ID,Network Access Profile Name,Authen-Failure-Code,Author-Failure-Code,Author-Data,NAS-Port,NAS-IP-Address,Filter Information,PEAP/EAP-FAST-Clear-Name,EAP Type,EAP Type Name,Reason,Access Device,Network Device Group
02/28/2012,00:31:52,Unknown NAS,,,,(Unknown),,,,,10.204.124.71,,,,,,,
02/28/2012,00:41:33,Unknown NAS,,,,(Unknown),,,,,10.204.124.71,,,,,,,
02/28/2012,00:42:18,Unknown NAS,,,,(Unknown),,,,,10.204.124.71,,,,,,,
Filtering is not applied.
Date
Time
Message-Type
User-Name
Group-Name
Caller-ID
Network Access Profile Name
Authen-Failure-Code
Author-Failure-Code
Author-Data
NAS-Port
NAS-IP-Address
Filter Information
PEAP/EAP-FAST-Clear-Name
EAP Type
EAP Type Name
Reason
Access Device
Network Device Group
02/28/2012
00:42:18
Unknown NAS
(Unknown)
10.204.124.71
02/28/2012
00:41:33
Unknown NAS
(Unknown)
10.204.124.71
02/28/2012
00:31:52
Unknown NAS
Am i missing any thing in configuration side with respect to ACS?
Thanks