Alert received that “Host Not Responding” able to ssh into box fine and app is up and running. No errors in newrelic-infra.log.
Restarting agent does not resolve the issue.
Host does not show in left hand “Hosts” menu in Infrastructure but does show in the list of hosts in the grid. Clicking the “See logs” link in the grid takes you to the logs for the box which has entries for the time period that new relic is reporting that the host is not responding.