AlmaLinux OS 9 must configure a DNS processing mode set be Network Manager.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-269288	SRG-OS-000480-GPOS-00227	ALMA-09-023560	SV-269288r1050170_rule	2025-02-20	1

Description
To ensure that DNS resolver settings are respected, a DNS mode in Network Manager must be configured.

ℹ️ Check
Note: If AlmaLinux OS 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). Verify that AlmaLinux OS 9 has a DNS mode configured in Network Manager. $ NetworkManager --print-config [main] dns=none If the "dns" key in the [main] section does not exist or is not set to "none" or "default", this is a finding.

ℹ️ Check

Note: If AlmaLinux OS 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). Verify that AlmaLinux OS 9 has a DNS mode configured in Network Manager. $ NetworkManager --print-config [main] dns=none If the "dns" key in the [main] section does not exist or is not set to "none" or "default", this is a finding.

✔️ Fix
Configure NetworkManager in AlmaLinux OS 9 to use a DNS mode. In "/etc/NetworkManager/NetworkManager.conf" add the following line in the "[main]" section: dns = none NetworkManager must be reloaded for the change to take effect. $ systemctl reload NetworkManager