Information
DoS is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity.
This requirement addresses the configuration of the operating system to mitigate the impact of DoS attacks that have occurred or are ongoing on system availability. For each system, known and potential DoS attacks must be identified and solutions for each type implemented. A variety of technologies exist to limit or, in some cases, eliminate the effects of DoS attacks (e.g., limiting processes or establishing memory partitions). Employing increased capacity and bandwidth, combined with service redundancy, may reduce the susceptibility to some DoS attacks.
Solution
Set the system to implement rate-limiting measures by adding the following line to '/etc/sysctl.conf' or a configuration file in the /etc/sysctl.d/ directory (or modify the line to have the required value):
net.ipv4.tcp_invalid_ratelimit = 500
Issue the following command to make the changes take effect:
# sysctl --system