NTP has no active system peer to receive clock information from the statically configured servers, peers, or local clocks. This event can be triggered by losing the path to a server or a server service stop. After this event, the accuracy of clock might drift.
Check reachability from switch to destination using ping. In case of ping failures, use traceroute to see if the network segments are dropping packets. If the network segments are OK, check for a possible service outage in the server.
Notice
No active NTP system peer exists to adjust the system clock.