STIGQter STIGQter: STIG Summary: Red Hat Enterprise Linux 9 Security Technical Implementation Guide Version: 2 Release: 9 Benchmark Date: 01 Jul 2026:

RHEL 9 must not forward IPv4 source-routed packets by default.

DISA Rule

SV-257964r1155739_rule

Vulnerability Number

V-257964

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

RHEL-09-253045

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Configure RHEL 9 to not forward IPv4 source-routed packets by default.

Create a configuration file if it does not already exist:

$ sudo vi /etc/sysctl.d/99-ipv4_accept_source_route.conf

Add the following line to the file:
net.ipv4.conf.default.accept_source_route = 0

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

$ sudo sysctl --system

Check Contents

Verify RHEL 9 does not accept IPv4 source-routed packets by default.

Check the value of the "accept source route" variable with the following command:

$ sudo sysctl net.ipv4.conf.default.accept_source_route
net.ipv4.conf.default.accept_source_route = 0

If "net.ipv4.conf.default.accept_source_route" is not set to "0" or is missing, this is a finding.

Vulnerability Number

V-257964

Documentable

False

Rule Version

RHEL-09-253045

Severity Override Guidance

Verify RHEL 9 does not accept IPv4 source-routed packets by default.

Check the value of the "accept source route" variable with the following command:

$ sudo sysctl net.ipv4.conf.default.accept_source_route
net.ipv4.conf.default.accept_source_route = 0

If "net.ipv4.conf.default.accept_source_route" is not set to "0" or is missing, this is a finding.

Check Content Reference

M

Target Key

5551