This error means that the TCP packets have no route (path) between our monitoring
location and your server or web site. There are many intermediate
networks through which TCP packets pass before they reach the destination
server. You can see these intermediate hosts/networks when you run a
'traceroute'. If one of the intermediate networks is
unavailable, your TCP packets may be lost and you get a 'No route to
host' error in your error log. This does not necessarily man your web site or server was down but rather that our system was not able to reach your web site or server due to this network problem.