Refer to
http://www.cisco.com/en/US/prod/collateral/netmgtsw/ps5698/ps6767/ps9911/product_bulletin_c25-616320.html
The optional Large Deployment add-on license allows a deployment to support more than 500 network devices. Only one Large Deployment license is required per deployment as it is shared by all instances.
The optional Security Group Access System license is required to enable Security Group Access (SGA) and 802.1ae (also known as MACSec) functionality. Only one Security Group Access System license is required per deployment as it is shared by all instances.
For 2 ACSs as HA pair, only 1 Large Deployment add-on license and 1 Security Group Access System license are enought for 1 HA pair? The keys are required for Master ACS?
