For systems using DNS resolution, at least two name servers must be configured.

From Oracle Linux 5 Security Technical Implementation Guide

Associated with: CCI-001182

SV-64547r1_rule For systems using DNS resolution, at least two name servers must be configured.

Vulnerability discussion

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.

Check content

Determine if DNS is enabled on the system. # grep dns /etc/nsswitch.conf If no line is returned, or any returned line is commented out, the system does not use DNS, and this is not applicable. Determine the name servers used by the system. # grep nameserver /etc/resolv.conf If less than two lines are returned that are not commented out, this is a finding.

Fix text

Edit /etc/resolv.conf and add additional "nameserver" lines until at least two are present.

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