The Photon operating system must log IPv4 packets with impossible addresses.

The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.

At the command line, run the following command to verify martian packets are logged:

# /sbin/sysctl -a --pattern "net.ipv4.conf.(all|default).log_martians"

Expected result:

net.ipv4.conf.all.log_martians = 1 net.ipv4.conf.default.log_martians = 1

If the "log_martians" kernel parameters are not set to "1", this is a finding.

Navigate to and open:

/etc/sysctl.d/zz-stig-hardening.conf

Add or update the following lines:

net.ipv4.conf.all.log_martians = 1 net.ipv4.conf.default.log_martians = 1

At the command line, run the following command to load the new configuration:

# /sbin/sysctl --load /etc/sysctl.d/zz-stig-hardening.conf

Note: If the file zz-stig-hardening.conf does not exist, it must be created.