Error Jmeter, Non HTTP response code: java.net.NoRouteToHostException.

When we tested a HTTP petition and we recived a response like Non HTTP response code: java.net.NoRouteToHostException,Non HTTP response message: No existe ninguna ruta hasta el «host».

In my case was that conection with the server has a firewall in middle and for that firewall we can not connect with the server.

The Firewall' rules was only 15 connections simultaneus and I was tested with 20 connections, for that rule the 5 connections could not connect successful and their results was HTTP petition and we recived a response like Non HTTP response code: java.net.NoRouteToHostException.