Conventions used

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

Code in text: 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: “Both modes use the same Linux device driver (accessible via /dev/net/tun), just with a different flag. The flag to use TAP mode is IFF_TAP, whereas the flag to use TUN is IFF_TUN.”

A block of code is set as follows:

from paramiko import SSHClient
client = SSHClient()
client.connect('10.1.1.1', username='user', password='pw')

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

import unittest
import mock
from paramiko import SSHClient
class TestSSHClient(unittest.TestCase):
    @mock.patch('paramiko.SSHClient.connect')
    def test_connect(self, mock_connect):

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

claus@dev:~$ sudo ip tuntap add dev tap0 mode tap
claus@dev:~$ sudo ip link set tap0 up
claus@dev:~$ ip link show tap0

Bold: Indicates a new term, an important word, or words that you see onscreen. For instance, words in menus or dialog boxes appear in bold. Here is an example: “Having included E5, S5, and L5, the Clos network will have now 50 connections.”

Tips or important notes

Appear like this.