STIGQter STIGQter: STIG Summary: Oracle Linux 9 Security Technical Implementation Guide Version: 1 Release: 6 Benchmark Date: 01 Jul 2026:

OL 9 must use a reverse-path filter for IPv4 network traffic, when possible, by default.

DISA Rule

SV-271871r1172843_rule

Vulnerability Number

V-271871

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

OL09-00-006027

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Configure OL 9 to use reverse path filtering on IPv4 interfaces by default.

Add or edit the following line in a single system configuration file in the "/etc/sysctl.d/" directory:

net.ipv4.conf.default.rp_filter = 1

Load settings from all system configuration files with the following command:

$ sudo sysctl --system

Check Contents

Verify OL 9 uses reverse path filtering on IPv4 interfaces with the following commands:

$ sysctl net.ipv4.conf.default.rp_filter
net.ipv4.conf.default.rp_filter = 1

If the returned line does not have a value of "1", or a line is not returned, this is a finding.

Vulnerability Number

V-271871

Documentable

False

Rule Version

OL09-00-006027

Severity Override Guidance

Verify OL 9 uses reverse path filtering on IPv4 interfaces with the following commands:

$ sysctl net.ipv4.conf.default.rp_filter
net.ipv4.conf.default.rp_filter = 1

If the returned line does not have a value of "1", or a line is not returned, this is a finding.

Check Content Reference

M

Target Key

5680