Logging and Monitoring Rules

Effective security requires visibility into firewall activity. Logging rules capture security events for analysis, compliance, and incident response. However, excessive logging can impact performance and create noise that obscures important events.

Log security-relevant events without overwhelming storage:

Log TCP SYN from any to web_server_ip port not in (80,443) # Unexpected ports
Log all from blocked_ip_list to web_server_ip  # Known bad actors
Log TCP from any to web_server_ip where packet_count > 10000  # High volume

Create separate logging for different severity levels:

Log priority high: all dropped packets to admin_ports
Log priority medium: connection_rate_exceeded events
Log priority low: successful connections from new_ip_addresses

Implement log rate limiting to prevent log flooding attacks:

Log all from any to web_server_ip limit rate 1000/minute