I curretly have two ACS servers. The primary server is running version 3.3.3 while the secondary is running 4.2 (recently updated) . The problem I am seeing is when both the primary and secondary are up and running, my users are unable to access any of the tacacs authenticated devices. The really strange thing I am seeing is that we have one network device that is configured to use only the primary tacacs server and when both the primary and secondary are running, authentication fails (even though the logs show on the primary "Authen OK"). When I shut down the secondary ACS server, everything works fine.
Please be aware that these two servers have been configured for replication and proxy distribution (even though its currently not working do to the different running versions)
Is this because the primary and secondary are running different versions? And why does auth fail when the primary and secondary are running and the network device is configured to only use the primary?? Any ideas?