48.5.4.3.4. Resource Management Options
The
xinetd
daemon can add a basic level of protection from Denial of Service (DoS) attacks. The following 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 bothxinetd.conf
and in the service-specific configuration files in thexinetd.d/
directory.cps
— Defines the maximum number of connections per second. This directive takes two integer arguments separated by white space. The first argument is the maximum number of connections allowed to the service per second. The second argument is the number of seconds thatxinetd
must wait before re-enabling the service. It accepts only integers as arguments and can be used in either thexinetd.conf
file or the service-specific configuration files in thexinetd.d/
directory.max_load
— Defines the CPU usage or load average threshold for a service. It accepts a floating point number argument.The load average is a rough measure of how many processes are active at a given time. See theuptime
,who
, andprocinfo
commands for more information about load average.
There are more resource management options available for
xinetd
. Refer to the xinetd.conf
man page for more information.