Using Cisco ISE as a generic RADIUS server

Cisco ISE is an identity-based policy server featuring a wide range of functions from RADIUS CLI authentication to workstation posturing. With just a base license it includes a full-featured RADIUS server and it is capable of performing trivial RADIUS tasks which would not require such a sophisticated product themselves. For the functions described in this article Cisco Secure ACS could have been commonly chosen some years earlier. ISE’s policy logic and web interface is quite different.

The following use cases are described:

• Cisco device access (admin login)

IOS Easy VPN Server with LDAP authentication

LDAP support for authentication and authorization was introduced in IOS 15.1(1)T.  In this article we are testing Cisco VPN client connection authenticated against Novell NetWare eDirectory.

Structure of the LDAP directory:

IOS Easy VPN with RADIUS, Cisco Secure ACS 5.1 and AAA cache

AAA Authorization and Authentication Cache was integrated in IOS 15.0(1)M. This feature enables the router to store AAA credentials in its cache after it received the RADIUS or TACACS+ reply to an AAA request. The cache can be used either for performance boost (avoiding sending requests to the AAA server) or for a fallback method in case the servers are unreachable. The mode depends on the order you place your authentication methods in the aaa commands (see below).

In this example we are caching TACACS admin users’ credentials (telnet, vty) and RADIUS VPN users’ credentials (IKE xauth). The VPN group is also defined on the RADIUS server.

Local user group-lock in IOS Easy VPN

Cisco router IOS Easy VPN Server

Group-Lock feature can also be used with local users, we can even create something like ‘local user groups’. Possible formats are:

name/group, name\group, name@group, or name%group