Network devices must use at least two NTP servers to synchronize time.

From Firewall Security Technical Implementation Guide

Part of Two NTP servers are not used to synchronize time.

SV-28651r4_rule Network devices must use at least two NTP servers to synchronize time.

Vulnerability discussion

Without synchronized time, accurately correlating information between devices becomes difficult, if not impossible. If logs cannot be successfully compared between each of the routers, switches, and firewalls, it will be very difficult to determine the exact events that resulted in a network breach incident. NTP provides an efficient and scalable method for network devices to synchronize to an accurate time source.

Check content

Review the configuration and verify two NTP servers have been defined. If the device is not configured to use two separate NTP servers, this is a finding.

Fix text

Configure the device to use two separate NTP servers.

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