17.4.3.4. Resource Management Options

The xinetd daemon can add a basic level of protection from a Denial of Service (DoS) attacks. Below is a list of directives which can aid in limiting the effectiveness of such attacks:
  • per_source — Defines the maximum number of instances for a service per source IP address. It accepts only integers as an argument and can be used in both xinetd.conf and in the service-specific configuration files in the xinetd.d/ directory.
  • cps — Defines the maximum of connections per second. This directive takes two integer arguments separated by white space. The first is the maximum number of connections allowed to the service per second. The second is the number of seconds xinetd must wait before re-enabling the service. It accepts only integers as an argument and can be used in both xinetd.conf and in the service-specific configuration files in the xinetd.d/ directory.
  • max_load — Defines the CPU usage threshold for a service. It accepts a floating point number argument.
There are more resource management options available for xinetd. Refer to the chapter titled Server Security in the Security Guide for more information, as well as the xinetd.conf man page.