V-279626

Discussion

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.

Check Content

For AHV, this requirement is Not Applicable.

Verify Nutanix OS protects against or limits the effects of DoS attacks by ensuring that a rate-limiting measures are enabled using the following command.

$ /sbin/sysctl -a | grep 'net.ipv4.tcp_invalid_ratelimit'
net.ipv4.tcp_invalid_ratelimit = 500

If "net.ipv4.tcp_invalid_ratelimit" has a value greater than "1000" or equal to "0", this is a finding.