We have an internal web application running in IIS 8 / Windows Server 2012. Our users are sporadically reporting seeing "This webpage is not available" on a very regular basis. Reloading in their browser of choice will generally cause the page to be loaded successfully, but this is still frustrating people.
Generally I would expect the server to be overwhelmed, but I've been watching resource monitor on the server for some time and I'm not seeing any unusual load. This is a Dell PowerEdge R720XD with 24GB of RAM and 2x Quad Core Xeons running at 1.8 GHz. It is only supporting a user load of about 40 individuals.
Where should I look to find out exactly what is causing this? I had very little luck with Google, and am more of a developer that a server administrator. Is there some logging I can set up that will shed some light? There are TONS of options in performance monitor. Should I be tracking some specific metrics there?