Tcpd also logs all connections, whether they were sucessful or failed. Those logs are useful in determining if the system is being probed or attacked. Also if the system is compromised the logs can help determine how and from where. This log should be monitored. The section below on syslog talks more on monitoring system logs.
System Logs Many of the programs on a Linux system write to log files.
These log files can contain generic information, to warnings and error messages about the system. The program syslogd runs in the background gathers all the messages and decides whether to log them, and if so which logs. The white space in the above line is a tab and spaces should not be used. At this point all unessecary program and services have been disabled and removed. Also any desireable programs have been installed and configured.