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Monitoring a website behind a firewall

Posted: Mon Jul 16, 2012 11:12 am
by naglink
Greetings all,

I just setup a new Nagios XI install, and I'm finding my way around. I've gotten monitoring up and running on several hosts, but I've run into a snag. I'm trying to monitor a website siting on a system that is behind a firewall. Eventually I may be about to open a port to allow Nagios through, but in the mean time I am trying to get monitoring setup for a website.

That site is accessible from the outside world through specific port, but most other types of traffic are denied. I've tried a few different methods to monitor the website, but each time I get nagios reporting that the system is unavailable. If you look at the services details on the view tab, it shows that HTTP is up, but the host itself shows as down with a message "Socket timeout after 10 seconds" . Is there a way to just monitor the HTTP connection, and not have the host itself flagged with a critical warning because it's no reachable? All we care about is making sure the website is up, nothing else.

Thanks in advance.

Re: Monitoring a website behind a firewall

Posted: Mon Jul 16, 2012 11:33 am
by lmiltchev
See if this is going to be a solution for you:

http://assets.nagios.com/downloads/nagi ... _In_XI.pdf

Re: Monitoring a website behind a firewall

Posted: Mon Jul 16, 2012 12:10 pm
by naglink
That looks like a great place to start, thank you. Since port 80 is blocked on that site, but another port is open, do you know if there is a way to have that service checking on the open port? I applied that fix, and it's still showing the host as down.

Thanks again for you help!

Re: Monitoring a website behind a firewall

Posted: Mon Jul 16, 2012 12:43 pm
by naglink
double-post

Re: Monitoring a website behind a firewall

Posted: Mon Jul 16, 2012 1:04 pm
by scottwilkerson
Go to
Configure -> CCM -> Hosts -> Modify
Change the following
check command = check_xi_host_http
$ARG1$ = -p 8888

Replace 8888 with the port in use

Re: Monitoring a website behind a firewall

Posted: Mon Jul 16, 2012 3:14 pm
by naglink
Thank you so much, that did the trick. Adding the port on the modification screen is exactly what it took. Consider this one solved.