• Dataplane CPU: Responsible for processing traffic, session management, and security policies.
  • Issue Faced:
    • Network slowdowns leading to an inability to log in to the firewall.
    • Only resolution was a failover to the secondary firewall.
  • Root Cause:
    • Increasing session count due to DNS forwarding.
    • Sessions were not closing properly.
  • Fix Implemented:
    • Removed DNS forwarding from domain controllers.
    • Result: Dataplane CPU dropped from 80% to 8%.
  • Next Steps:
    • Test setting timeouts on inactive sessions next week.
  • Key Takeaway:
    • High dataplane CPU usage can severely impact firewall performance.
    • Session management (timeouts, proper closure) is critical for stability.