Cisco ASA and PIX Firewall Handbook

9-2. Generating Logging Messages

The firewall uses logging to send system messages to one or more logging destinations, where they can be collected, archived, and reviewed.

Messages are generated according to a severity level, specified by a number (0 through 7) or a keyword, as shown in Table 9-1.

Table 9-1. System Message Severity Levels

Severity Level	Description
0: emergencies	The system is unusable
1: alerts	Immediate action is required
2: critical	A critical condition exists
3: errors	Error message
4: warnings	Warning message
5: notifications	A normal but significant condition
6: informational	Information message
7: debugging	Debug output and very detailed logs

Logging messages can be sent to any of the following destinations:

• The firewall console

• Telnet ...