For RHEL 8 systems using Domain Name Servers (DNS) resolution, at least two name servers must be configured.
An XCCDF Rule
Description
<VulnDiscussion>To provide availability for name resolution services, multiple redundant name servers are mandated. A failure in name resolution could lead to the failure of security functions requiring name resolution, which may include time synchronization, centralized authentication, and remote system logging.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-230316r627750_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Configure the operating system to use two or more name servers for DNS resolution.
By default, "NetworkManager" on RHEL 8 dynamically updates the /etc/resolv.conf file with the DNS settings from active "NetworkManager" connection profiles. However, this feature can be disabled to allow manual configurations.
If manually configuring DNS, edit the "/etc/resolv.conf" file to uncomment or add the two or more "nameserver" option lines with the IP address of local authoritative name servers. If local host resolution is being performed, the "/etc/resolv.conf" file must be empty. An empty "/etc/resolv.conf" file can be created as follows: