This document describes how to work around a scenario where the Administrator is not able to authenticate to a Standby Cisco Adaptive Security Appliance (ASA) in a Failover Pair due to the fact that the Authentication, Authorization, and Accounting (AAA) server is located on a remote location through a LAN-to-LAN (L2L).
Although fallback to LOCAL authentication can be used, RADIUS Authentication for both units is preferred.
Cisco recommends that you have knowledge of these topics:
Network Address Translation (NAT)
This document is not restricted to specific software and hardware versions.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
The RADIUS server is located on the outside of the Failover Pair and it is reachable through a L2L tunnel to 220.127.116.11. This is what causes the probem because the standby ASA tries to reach it through its own outside interface but there is no tunnel built on it at this point; for it to work, it should send the request to the active interface so the packet can flow across the VPN but the routes are replicated from the active unit.
One option is to use a fake IP address for the RADIUS Server on the ASAs and point it to the inside. Therefore, the source and destination IP address of this packet can be translated on an internal device.
interface FastEthernet0/0 ip address 192.168.1.3 255.255.255.0 no ip redirects no ip unreachables ip nat enable duplex auto speed auto
ip access-list extended NAT permit ip 192.168.1.0 0.0.0.255 host 192.168.200.250
ip nat source list NAT interface FastEthernet0/0 overload ip nat source static 192.168.200.11918.104.22.168
aaa authentication serial console LOCAL aaa authentication ssh console RADIUS LOCAL aaa authentication telnet console RADIUS LOCAL aaa authentication http console RADIUS LOCAL aaa authentication enable console RADIUS LOCAL
Note: The 192.168.200.250 IP address was used in the example, but any unused IP address works.
Use this section in order to confirm that your configuration works properly.
The Output Interpreter Tool (registered customers only) supports certain show commands. Use the Output Interpreter Tool in order to view an analysis of show command output.
Router# show ip nat nvi tra Pro Source global Source local Destin local Destin global udp 192.168.1.3:1025 192.168.1.1:1025 192.168.200.250:1812 192.168.200.1:1812 --- 192.168.200.1 192.168.2.1 --- --- --- 192.168.200.250 192.168.200.1 --- ---
There is currently no specific troubleshooting information available for this configuration.