In this chapter, we majorly focused on how we can attack the external network and to implement this attack. We studied a few fundamentals such as port forwarding, which means redirecting the request from one port to the other. We even studied external backdoors and also how to exploit them, and we saw they are not different to internal backdoors. Then, moving ahead to another aspect of attacking the network, we learned about IP forwarding, wherein we saw how to determine the path through which the packet flows. We also implemented real-life examples to see how this works. In the next chapter, we are going to look at techniques to access the victim's system even after they are not running software on their system.