You plan to implement Cisco Identity Based Networking Services on a Cisco Catalyst 3850 Series...

The ‘aaa session-id common’ command is essential when implementing Cisco Identity Based Networking Services (IBNS) with downloadable ACLs on a Cisco Catalyst 3850 Series Switch. This command configures the switch to use a common session identifier for all AAA (Authentication, Authorization, and Accounting) transactions. This is important for downloadable ACLs because it ensures that the correct policies are applied consistently across different sessions and services.