Network Address Translation (NAT) is typically used for translating a range of private IPv4 addresses to publicly routable IPv4 addresses. But it can also mean a translation between IPv4 to IPv6, such as at a carrier edge when they use IPv6 inside of the network that needs to be translated to IPv4, when the packet leaves the network. Sometimes, NAT6to6 is used as well for security reasons.

Security is a continuous process that integrates all the aspects of networking, including automation and Python. This book aims at using Python to help you manage the network; security will be addressed as part of the chapter such as using SSHv2 over telnet. We will also look at how we can use Python and other tool chains to gain visibility in the network.