I have a proxy server (ubuntu 12.04 + nginx 1.4.4). In the nginx access log, I see this entry every 5 minutes: 127.0.0.1 - - [07/Jan/2014:18:10:02 +0000] "GET / HTTP/1.1" 403 168 "-" "Mozilla/5.0 (ISPConfig monitor)" In the nginx error log, I also see this entry every 5 minutes: 2014/01/07 17:45:02 [error] 18832#0: *928 directory index of "/usr/share/nginx/www/" is forbidden, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost" What are these? What does ISPConfig do every 5 minutes? Maybe the webalizer working? But what about the ERROR log? The main reason I am investigating this is because the server every few hours stops responding to the web browser, although I am able to have ftp access and SSH. Besides the above strange entries, I do not see anything suspicious in the access and error log files.