From within our production network, we make calls to other servers owned by us at different locations. Several of our services also make calls to these other servers hosted in other destinations. For instance, our mail server is in the US while our proxy server (squid proxy software running in one of the servers) is in India.
At times, the server in India would not be able to reach the US server. But the US server would be absolutely reachable from other network connections. While we suspect the data center network here, we would like to be aware of the issue as soon as it occurs. Is there a way to monitor the reachability of these external servers from our proxy server? And also, alert us when any of the servers are not reachable.
While it is possible to whip up some code with ping/curl/wget, I really wanted to know if something out there is already available to solve the problem.