The Cisco ISR 4000 Series router must compare internal information system clocks at least every 24 hours with an authoritative time server.

From Cisco IOS XE Release 3 NDM Security Technical Implementation Guide

Associated with: CCI-001891

SV-88715r1_rule The Cisco ISR 4000 Series router must compare internal information system clocks at least every 24 hours with an authoritative time server.

Vulnerability discussion

Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside of the configured acceptable allowance (drift) may be inaccurate. Additionally, unnecessary synchronization may have an adverse impact on system performance and may indicate malicious activity. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network.

Check content

Verify that at least two NTP servers are configured and that system clocks update the time every 24 hours. The configuration should look similar to the example below: ntp authentication-key 1 md5 072C285F4D06 7 ntp authenticate ntp trusted-key 1 ntp server 1.1.1.1 key 1 If there are not at least two NTP servers configured, and clocks are updated at least every 24 hours, this is a finding.

Fix text

Configure the router to use NTP. The configuration should look similar to the example below: ntp authentication-key 1 md5 072C285F4D06 7 ntp authenticate ntp trusted-key 1 ntp server 1.1.1.1 key 1

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.