What is the primary benefit of using a Policy Set compared to the legacy 'Rule-Based' approach in ISE?
Policy Sets group multiple authentication and authorisation policy objects into a single reusable container, so a change applies everywhere the set is referenced. This delivers the modularity and logical organisation that the legacy rule-based model, with its flat per-rule structure, cannot.
Why this answer
The primary benefit of a Policy Set over the legacy rule-based approach is improved logical organization and modularity. Policy Sets let you group authentication and authorization rules by use case (e.g., wired 802.1X, wireless guest, VPN) with their own conditions, making large deployments easier to manage and troubleshoot.
Exam trap
SISE often tests whether candidates understand that Policy Sets are an organizational and modularity improvement, not a licensing, identity-source, or performance feature.
How to eliminate wrong answers
Option B is wrong because Policy Sets do not change licensing requirements; licensing is based on node counts and features, not on policy structure. Option C is wrong because Policy Sets do not eliminate the need for external identity sources; they still rely on AD, LDAP, or other stores for authentication. Option D is wrong because Policy Sets do not inherently improve performance; they are an organizational construct, and performance depends on PSN sizing and deployment design.