TCP Wrappers and Enhanced Logging

If certain types of connections are of more concern than others, the log level can be elevated for that service using the severity option.

For this example, assume that anyone attempting to connect to port 23 (the Telnet port) on an FTP server is a cracker. To denote this, place an emerg flag in the log files instead of the default flag, info, and deny the connection.

To do this, place the following line in /etc/hosts.deny:

in.telnetd : ALL : severity emerg

This uses the default authpriv logging facility, but elevates the priority from the default value of info to emerg, which posts log messages directly to the console.