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Cisco Secure ACS 5.3 and GNS3


In a previous post I showed how I installed ACS in VBox. The reason I wanted it in VBox was so I could add it to GNS3 topology as a host. GNS uses first NIC in of a VM as a “management” NIC and adds a second NIC for linking within the topology.  ACS supports only single NIC (even the hardware appliance that comes with 4 NICs, has 3 of them disabled). “Runtime”  is the process that listens to and processes TACACS and RADIUS requests. It gets “bound” to the IP addresses configured during the initial setup. When ACS is added to GNS and second NIC installed and configured, the "runtime" still listens only on the first NICs IP address. Configuring the second NIC, disabling the first one and restarting ACS application results in "runtime" not starting at all.

To get around that, I needed to do the following at the ACS’s console once ACS was added to GNS as a VBox host:

1.         Configure second NIC with the same IP address as the first one

# configure terminal
# interface gigabitEthernet 1
# ip address 10.0.0.5 255.255.255.0 (or whatever address you used)
don't restart the services
#exit
#copy running-config startup-config

2.       Restart the VM and login to ACS

# configure terminal
# interface gigabitEthernet 0
# shutdown
don't restart the services
# end

3.       Restart ACS app (not the VM just the application)

# acs stop
# acs start

It takes a few minutes to stop and restart

4.       Confirm all ACS processes are started

# show application status acs

5.       Confirm ACS is listening on runtime ports (TCP 49 for TACACS)

# show ports

When you do “show interfaces”, ACS displays real interface names (eth0 and eth1) however to configure them you need to use “gigabitEthernet”.  

You could also try editing the startup-config file by booting to a Live Linux CD and editing the file using VI or some other text editor. The config file is stored in /_storedconfig partition. 
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