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 configure a DNS processing mode in Network Manager.

DISA Rule

SV-257949r1134947_rule

Vulnerability Number

V-257949

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

RHEL-09-252040

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Configure NetworkManager in RHEL 9 to use a DNS mode.

In "/etc/NetworkManager/NetworkManager.conf", add the following line in the "[main]" section:

dns = <dns processing mode>

Where <dns processing mode> is default, none, or systemd-resolved.

NetworkManager must be reloaded for the change to take effect.

$ sudo systemctl reload NetworkManager

Check Contents

Verify that RHEL 9 has a DNS mode configured in Network Manager.

$ NetworkManager --print-config
[main]
dns=none

If the dns key under main does not exist or is not set to "default", "none", or "systemd-resolved", this is a finding.

Note: If RHEL 9 is configured to use a DNS resolver other than Network Manager, the configuration must be documented and approved by the information system security officer (ISSO).

Vulnerability Number

V-257949

Documentable

False

Rule Version

RHEL-09-252040

Severity Override Guidance

Verify that RHEL 9 has a DNS mode configured in Network Manager.

$ NetworkManager --print-config
[main]
dns=none

If the dns key under main does not exist or is not set to "default", "none", or "systemd-resolved", this is a finding.

Note: If RHEL 9 is configured to use a DNS resolver other than Network Manager, the configuration must be documented and approved by the information system security officer (ISSO).

Check Content Reference

M

Target Key

5551