Non HTTP response code: java.net.BindException Response message during load test in JMeter

I want to do a load test with 1500VU in JMeter but I am NOT able to ramp up more than 1000VU.

I did some R&D and used two LGs (LG1 with 2 cores CPU and LG2 with 4 cores CPU) and I observed using LG1, I am able to ramp up upto 1000VU with 100% CPU usage(no exceptions), but LG2 starts throwing "Non HTTP response code: java.net.BindException" even after 600VU.

Even though the config is high for LG2 than LG1, LG1 is performing better.

Can anyone help to answer below two issues:

1. Why LG2 is throwing BindException and what's the solution for that?
2. Why LG2 with 4core is not able to ramp up more than LG1 with 2core?

I guess you're trying to run JMeter on Windows. If this is the case consider the following steps:

1. Increase ephemeral ports range
2. Decrease the maximum time the connection spends in TIME_WAIT state
3. Increase the maximum number of network connections if it's below 200

If you cannot do any of these due to lack of administrative permissions - the only option would be get more machines and run your JMeter test in distributed mode