IP Address Spoofing - Legitimate Uses of IP Spoofing

Legitimate Uses of IP Spoofing

Spoofed IP packets are not a priori evidence of malicious intent, however. In performance testing of websites, hundreds or even thousands of "vusers" (virtual users) may be created, each executing a test script against the Web site under test, in order to simulate what will happen when the system goes "live" and a large number of users log on at once.

Since each user will normally have their own IP address, commercial testing products (such as HP's Loadrunner software) can use IP spoofing, allowing each vuser its own "return address", as well.