For LR 11.0x and 11,5x and for ALM-PC 11.0x and 11.5x, the Max is 254 IP's Per load generator (LG). Even though you can run the wizard and install/create more than 254 IPs. When you run your test the Controller will only spoof 254 PER Load Generator. All IPs must be valid IPs that could be used for a Real Machine

Additionally, keep in mind, that the number of IP's and Vusers that can run in a load test will be limited by the system resources (CPU, memory, etc.) of the LG's.

So for you to Run tests with 500 IP's address you Must use 2 LG's