Cisco ACS 5.1 can act as radius proxy server, it accepts the authentication, accounting, authorization request from the NAS and forwards it to external radius server. It accepts the failure or success results of the requests and sends back to NAS.
ACS can simultaneously act as a proxy server to multiple external RADIUS servers.
Steps to create proxy server:-
Go to Network Resources > External RADIUS Servers> create > click the external radius server name and edit Name----external radius server
Ip address: x.x.x.x
Shared secret key: cisxx123
Advance options:
Authentication port:1812
Acct port:1813
Server timeout: default is 5 sec (can vary from 1 to 120 sec)
Connection attempts: default is 3 (can vary from 1 to 10)
Go to access policy> create a new service using (User Selected Service Type—RADIUS Proxy) (don't user predefined template) > Select the external RADIUS servers to be used for proxy and move them to the Selected External RADIUS Servers list.
Before you do above mentioned steps, please do verify that you can ping tp external radius server through ACS 5.1. Go to launch monitoring and reports > connectivity > type in ip address of radius server and ping.
Scenario 2:
Problem:
The basic Summary is that User want to have TACACS+ and local login to the router over the vty lines. So I made the two groups below. Goody obviously is what is going to use TACACS and Console uses the local logins. I split them between 0-4 and 5-15. It seems that whichever one is higher get the first priority for authentication. If I move Console to 0-4, then local users work and TACACS do not. If I have
Goody at 0 4, then TACACS works, but local does not. I know I'm probably missing something simple. Having two TACACS servers, I doubt both will ever be down, but in the event I would like Local
usernames to work. If I apply an access list to 0 4 and use SSH, and a different access list to 5 15 and use telnet it seems to work that way but doesn't help me if the internet goes down and I am onsite trying to
access the router via SSH.
aaa authentication login Goody group tacacs+ local
aaa authentication login Console local
line con 0
login authentication Console
line aux 0
line vty 0 4
session-timeout 7
exec-timeout 5 0
login authentication Goody
transport input ssh
line vty 5 15
session-timeout 7
exec-timeout 5 0
login authentication Console
transport input ssh
Solution:
Correct me if I not understanding this correctly but you want to use TACACS servers for ssh/console type authentication and if they fail, you want the network device to use its local database. If that is correct then
you should not need to split the lines and assign them different authentication lists. The first commend that you have:
aaa authentication login Goody group tacacs+ local
Lists both the tacacs+ and the local database as possible authentication methods. They will be processed in the order they are configured, so the device will:
1. Utilize your TACACS+ servers
2. If the TACACS+ servers become unreachable then the local data base will be used
You can test this by assigning "Goody" to all of your vty lines and then make your TACACS+ servers unavailable. To make that possible you can:
- Reboot the server
- Shutdown the server interface
- Disconnect the network device from its uplink
- Create an access-list on the uplink interface and block connection to the IP addresses of the TACACS+ servers
