Appache JMeter does not send http requests to my localhost

I have a project for checking the scalability and availability of the cloud servers.

I have two two servers reserved in Apache CloudStack and I want to check if these servers are able to face very high load. I think to execute stress and load testing to this host from my GUI jmeter. But jmeter gave me error which is known as non http request response code and connection refuse. If I try to test any website, they test them and there is no error and all the signs are green but when I test the same local server that run jmeter, it did not test and give me error and red sign I hope you help on this problems since it is the main concept of my master thesis.