It is important that key block ranges are explicitly configured on systems before they are first started. This is because after a system is started for the first time, the key block range allocated to it cannot be removed. This restriction is necessary because as soon as a system is started, entities drawn from the key block range may be created, and so removing a key block range allocation could cause issues.
The key block range configuration for a system is performed using the CTM setup tool. See section 5.3.4 - CTM Setup Tool for information on using this tool.