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

RHEL 9 systems using Domain Name Servers (DNS) resolution must have at least two name servers configured.

DISA Rule

SV-257948r1045004_rule

Vulnerability Number

V-257948

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

RHEL-09-252035

Severity

CAT II

CCI(s)

CCI-000366 - Implement the security configuration settings.

Weight

Fix Recommendation

Configure the operating system to use two or more name servers for DNS resolution based on the DNS mode of the system.

If the NetworkManager DNS mode is set to "none", add the following lines to "/etc/resolv.conf":

nameserver [name server 1]
nameserver [name server 2]

Replace [name server 1] and [name server 2] with the IPs of two different DNS resolvers.

If the NetworkManager DNS mode is set to "default", add two DNS servers to a NetworkManager connection using the following command:

$ nmcli connection modify [connection name] ipv4.dns [name server 1],[name server 2]

Replace [name server 1] and [name server 2] with the IPs of two different DNS resolvers. Replace [connection name] with a valid NetworkManager connection name on the system. Replace ipv4 with ipv6 if IPv6 DNS servers are used.

Check Contents

Note: If the system is running in a cloud platform and the cloud provider gives a single, highly available IP address for DNS configuration, this control is Not Applicable.

Verify the name servers used by the system with the following command:

$ grep nameserver /etc/resolv.conf

nameserver 192.168.1.2
nameserver 192.168.1.3

If fewer than two lines are returned that are not commented out, this is a finding.

Vulnerability Number

V-257948

Documentable

False

Rule Version

RHEL-09-252035

Severity Override Guidance

Check Content Reference

Target Key

5551