Planning a new DHCP implementation or revamping your existing DHCP implementation requires a good understanding of how DHCP works. You need to know the following information:
How DHCP messages are sent and received
How DHCP relay agents are used
How multiple servers should be configured
When a DHCP client is started, it uses network broadcasts to obtain or renew a lease from a DHCP server. These broadcasts are in the form of DHCP messages. A client obtains its initial lease as shown in Figure 25-1. Here, the client broadcasts a DHCP Discover message. All DHCP servers on the network respond to the broadcast with a DHCP Offer message, which offers the client an IP lease. The client accepts ...