The system must log martian packets.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22418	GEN003611	SV-45728r1_rule		Low

Description
Martian packets are packets containing addresses known by the system to be invalid. Logging these messages allows the SA to identify misconfigurations or attacks in progress.

STIG	Date
SUSE Linux Enterprise Server v11 for System z Security Technical Implementation Guide	2018-09-19

Details

Check Text ( C-43095r1_chk )
Verify the system logs martian packets. # grep [01] /proc/sys/net/ipv4/conf/*/log_martians|egrep "default|all" If all of the resulting lines do not end with "1", this is a finding.

Fix Text (F-39126r1_fix)
Configure the system to log martian packets. Edit /etc/sysctl.conf and add a setting for "net.ipv4.conf.all.log_martians=1" and "net.ipv4.conf.default.log_martians=1". Reload the sysctls. Procedure: # sysctl -p