STIGQter STIGQter: STIG Summary: Cloud Linux AlmaLinux OS 9 Security Technical Implementation Guide Version: 1 Release: 7 Benchmark Date: 01 Jul 2026:

AlmaLinux OS 9 must log packets with impossible addresses.

DISA Rule

SV-269251r1050133_rule

Vulnerability Number

V-269251

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

ALMA-09-019380

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Configure AlmaLinux OS 9 to log martian packets.

Create a numbered *.conf file in /etc/sysctl.d/ with the following content:

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

The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command:

$ sysctl --system

Check Contents

Verify AlmaLinux OS 9 logs martian packets.

Check the value of the "log_martians" variables with the following command:

$ sysctl -a | grep log_martians

net.ipv4.conf.all.log_martians = 1
net.ipv4.conf.default.log_martians = 1
net.ipv4.conf.enp1s0.log_martians = 1
net.ipv4.conf.lo.log_martians = 1

If the returned lines do not all have a value of "1", this is a finding.

Vulnerability Number

V-269251

Documentable

False

Rule Version

ALMA-09-019380

Severity Override Guidance

Verify AlmaLinux OS 9 logs martian packets.

Check the value of the "log_martians" variables with the following command:

$ sysctl -a | grep log_martians

net.ipv4.conf.all.log_martians = 1
net.ipv4.conf.default.log_martians = 1
net.ipv4.conf.enp1s0.log_martians = 1
net.ipv4.conf.lo.log_martians = 1

If the returned lines do not all have a value of "1", this is a finding.

Check Content Reference

M

Target Key

5664