Internal networks are usually set up as either shared or switched.

  • Shared networks are more common.
  • They allow every host on the network segment to view every packet on the network, regardless of whether it is meant for that machine.
  • This encourages eavesdropping on your network.

Switched networks are designed so that only the intended participants have access to view the packets destined to them, thus limiting the possibility of eavesdropping. This is usually accomplished by a network device called a switch, which forwards packets based on node-specific hardware addresses.