IP ID(entification) Field
IP ID is a 16-bit field in the IPv4 header which is related with IP fragmentation. We won’t dig deeper what is IP ID field in this article. But you just have known that (randomly created initial) IP ID value -mostly- will be incremented by one for each IP packet arrived to the victim host. (For more information about IP ID field: *https://www.cellstream.com/intranet/reference-reading/tipsandtricks/314-the-purpose-of-the-ip-id-field-demystified.html, https://tools.ietf.org/html/rfc6864)*