Figure 4-1: An example of a client/server relationship on the same subnet. Because the client and server are on a common subnet, they may exchange information freely . Notice that the client uses the server's IP address as its DNS server.
Figure 4-2: An example of a client/server relationship on two different subnets. In order to exchange information, the client and server must go through a third party, a router, which forwards packets between the two.