Tapping into network traffic

As a network 007, our objective of gathering evidence can only be met if we dive into the data packets that flow across the network. To do this, we need to enhance our understanding of networks and the technology behind hubs and switches on the network.

In early networks, computers connected to each other via co-axial cables, followed by a switchover to the star topology and the use of Ethernet hubs. The following diagram shows a basic co-axial network:

The bus topology gave way to the star topology, as depicted in the following diagram:

In such a case, all the network traffic is broadcast to each and every node on the network and it is expected that the correct node will collect the traffic that is meant for it. In such a situation, if any network interface card (NIC) is in the promiscuous mode, it is able to capture any traffic that is meant for other nodes on the network. Software network sniffing tools, such as Wireshark, will automatically put the network...