I'm trying to load test with 3 remote servers, after test ends all the requests are shown in result tree, but I cannot find out which ip address (remote server) sent the request.
for example if I send one request from each remote server, then I see three total request in result tree, but I cannot understand which is for which
Use __machineName() or __machineIP() functions as prefix or postfix for your Sampler labels - this way you will be able to distinguish the results coming from different remote slaves.
Check out Apache JMeter Functions - An Introduction to learn more about JMeter Functions concept.