| Verify OL 8 does not respond to ICMP echoes sent to a broadcast address. |
Check the value of the "icmp_echo_ignore_broadcasts" variable with the following command:
$ sudo sysctl net.ipv4.icmp_echo_ignore_broadcasts
net.ipv4.icmp_echo_ignore_broadcasts = 1
If the returned line does not have a value of "1", a line is not returned, or the retuned line is commented out, this is a finding.
Check that the configuration files are present to enable this network parameter.
$ sudo grep -r net.ipv4.icmp_echo_ignore_broadcasts /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf
/etc/sysctl.d/99-sysctl.conf: net.ipv4.icmp_echo_ignore_broadcasts = 1
If "net.ipv4.icmp_echo_ignore_broadcasts" is not set to "1", is missing or commented out, this is a finding.
If conflicting results are returned, this is a finding.