To get the most out of this book

To understand the content of this book, it is recommended that you have basic knowledge of computer networks. If you are certified with CCNA network and security, that will be a good foundation for you to advance your knowledge about computer networks by reading this book.

As you know, it does not make sense to learn about computer networks without doing any practical work. Therefore, it is suggested that you practice TCP/IP, IP Packet Flow, Basic network design and setting up a LAN with at least a Cisco switch and router. Download emulators and simulators such as PuTTY and Tera Term, Packet Tracer and GNS3, Wireshark, Nmap, Nessus. All of the download links are included in the book.

Download the color images

We also provide a PDF file that has color images of the screenshots/diagrams used in this book. You can download it from https://www.packtpub.com/sites/default/files/downloads/PracticalNetworkScanning_ColorImages.pdf.

Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "For Linux, sudo iptables -L lists your current rules in iptables."

Any command-line input or output is written as follows:

netstat -antp | grep "LISTEN"

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example:

Most of us share our personal information on many web portals by clicking I Agree or I Accept the Terms and Conditions

Warnings or important notes appear like this.

Tips and tricks appear like this.