To use Scapy to identify discrepancies in TTL responses, you will need to have both a remote system that is running a Linux/Unix operating system and a remote system that is running a Windows operating system available for analysis. In the examples provided, an installation of Metasploitable2 and an installation of Windows XP are used. For more information on setting up systems in a local lab environment, refer to the Installing Metasploitable2 and Installing Windows Server recipes in Chapter 1, Getting Started. Additionally, this section will require a script to be written to the filesystem using a text editor such as Vim or GNU nano. For more information on writing scripts, refer to the Using text editors (Vim and GNU nano) recipe in Chapter 1, Getting Started.