V-279625

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. Managing excess capacity ensures that sufficient capacity is available to counter flooding attacks. Employing increased capacity and service redundancy may reduce the susceptibility to some DoS attacks. Managing excess capacity may include, for example, establishing selected usage priorities, quotas, or partitioning.

Check Content

Verify Nutanix OS is configured to use syncookies. 

1. For AOS, Prism Central, and Files, verify the saved value of TCP syncookies using the following command.

$ sudo grep -i net.ipv4.tcp_syncookies /etc/sysctl.conf /etc/sysctl.d/* | grep -v '#' 
/etc/sysctl.d/99-salt.conf:net.ipv4.tcp_syncookies = 1

2. Verify AHV is configured to use syncookies using the following command.

$ sysctl net.ipv4.tcp_syncookies 
net.ipv4.tcp_syncookies = 1 

$ sudo grep -i net.ipv4.tcp_syncookies /etc/sysctl.conf /etc/sysctl.d/* | grep -v '#' 

If the value of syncookies is not set to "1", this is a finding.