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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-257949	RHEL-09-252040	SV-257949r925834_rule		Medium

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

STIG	Date
Red Hat Enterprise Linux 9 Security Technical Implementation Guide	2023-12-01

Details

Check Text ( C-61690r925832_chk )
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 "none" or "default", this is a finding.

Fix Text (F-61614r925833_fix)
Configure NetworkManager in RHEL 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. $ sudo systemctl reload NetworkManager