As explained on the proxies help page, the free companion program PVProxy runs on servers behind firewalls and allows testing of servers and services on protected local networks.
Proxy usage is available only in the 'full' version of ProbeView.
When testing a target associated with a proxy, ProbeView usually uses a small number of "built-in" request messages: 'ICMP Ping' and 'TCP Ping'. However, the free PVProxy software, which is available for both Windows and Mac OS X, can be extended to allow advanced users and network administrators to test other network functions behind routers and firewalls.
A 'proxy extension' is a small piece of code that responds to proxy messages other than the built-in message types. You could, for example, write a proxy extension called "dbok" that runs a SQL query to determine if your database is on-line and functional. You then run PVProxy and your new extension on a server behind your router or firewall. Then add a target of type "proxy extension", and along with the usual hostname and port number, you provide the name of the extension, in this case, "dbok".
When ProbeView sends the test request (as a URL) to the PVProxy server, your extension code will be invoked and your code is responsible for performing your particular test and replying with its result. This is completely documented in the free downloads at our support website.
For more information or to obtain the free PVProxy software and sample code, visit the GroupWyse web site at http://groupwyse.com.
In the full version of ProbeView, the free PingView program can be used in conjuntion with PVProxy to monitor large networks. In this manner, a single ProbeView target can represent dozens or even hundreds of servers behind a firewall.
See the "Subordinate Targets" for more information about PingView server targets.