ACS Licensing and deployment sizes

The large deployment license is required per deployment if the deployment will control more than 500 nodes. If your had more than 500 AAA client devices (talking about switches, routers, etc. and not end-hosts or end-users), then they would need ONE Large Deployment license PER DEPLOYMENT.

If the customer has two ACS servers in the same deployment so one of them is a primary and the other is a secondary and they synchronize between each other, this is a deployment. A primary and all the secondary ACS that are kept in synchronized status by the primary consist a deployment.

The rule is the following: if there is more than 500 AAA clients (networking devices) in the same deployment, then they would need a Large Deployment license installed on the primary ACS.

If they didn't want to buy the Large Deployment license, then they would need to create two separate deployments each having a primary server only. However in this case there would be no configuration synchronization between the two servers so each and every user, policy and other settings must be configured on both appliances manually.