Understanding traffic flow on the network will give you better understanding of not only what is going on within the network, but will also give you clues as to what you may want to go after during the penetration test. Traffic sniffers allow us to monitor or capture traffic on the network to see what is happening among the hosts on the network. They work in a couple of different ways, depending on whether you are just looking at the traffic, or if you want to look and potentially change what you see before it ends up going to its ultimate destination. This is the whole idea around spoofing and man-in-the-middle attacks (MiTM), which we will discuss in this chapter.
The following topics will be discussed in this chapter:
- Traffic sniffing tools and techniques
- Tcpdump and filters
- Understanding and performing spoofing attacks
- MiTM attacks
