You work as a Penetration Tester for the Infosec Inc. Your company takes the projects of security auditing. Recently, your company has assigned you a project to test the security of the we-aresecure.com Web site. For this, you want to perform the idle scan so that you can get the ports open in the we-are-secure.com server. You are using Hping tool to perform the idle scan by using a zombie computer. While scanning, you notice that every IPID is being incremented on every query, regardless whether the ports are open or close. Sometimes, IPID is being incremented by more than one value.

What may be the reason?