PREP: Architecture Reference

Architecture Diagram

ISE 8-Node Distributed Deployment

Key Points to Highlight:

  • MNT nodes (red) are MONITORING only - they don’t process authentications

  • PSNs (blue) handle all RADIUS - they were never impacted

  • NetScaler provides VIP load balancing - resilient architecture

Appendix: ISE Service Architecture

┌─────────────────────────────────────────────────────────────┐
│                    ISE Node Roles                           │
├─────────────────────────────────────────────────────────────┤
│ PAN (Policy Admin Node)                                     │
│   - Policy configuration and distribution                   │
│   - NOT involved in real-time authentication                │
├─────────────────────────────────────────────────────────────┤
│ PSN (Policy Service Node)  ← HANDLES ALL AUTHENTICATION     │
│   - RADIUS server                                           │
│   - Real-time 802.1X processing                             │
│   - 4 nodes behind NetScaler VIPs                           │
├─────────────────────────────────────────────────────────────┤
│ MNT (Monitoring Node)  ← THIS IS WHERE THE ISSUE WAS        │
│   - Session logging and reporting                           │
│   - Does NOT affect authentication                          │
│   - Primary + Secondary for redundancy                      │
└─────────────────────────────────────────────────────────────┘

CRITICAL DISTINCTION:
- MNT issues affect VISIBILITY (logs, reports)
- MNT issues do NOT affect AUTHENTICATION (network access)