Adding, Modifying, or Removing DHCP

DHCP automatically assigns TCP/IP addressing to computers when they join the network and automatically renews the addresses before they expire. The advantage of using DHCP is the reduced number of addressing errors, which makes network maintenance much easier.

One of the biggest benefits of using DHCP is that the reconfiguration of IP addressing can be performed from a central location, with little or no effect on the clients. In fact, you can reconfigure an entire IP addressing system without the users noticing. As always, a cost is associated with everything good, and with DHCP, the cost is increased network traffic.

You know what the function of DHCP is and the service it provides to the network, but what impact does the DHCP service have on the network itself? Some network services can consume huge amounts of network bandwidth, but DHCP is not one of them. The traffic generated between the DHCP server and the DHCP client is minimal during normal usage periods.

The bulk of the network traffic generated by DHCP occurs during two phases of the DHCP communication process: when the lease of the IP address is initially granted to the client system and when that lease is renewed. The entire DHCP communication process takes less than a second, but if there are a very large number of client systems, the communication process can slow down the network.

For most network environments, the traffic generated by the DHCP service is negligible. For environments in which DHCP traffic is a concern, you can reduce this traffic by increasing the lease duration for the client systems, thereby reducing communication between the DHCP client and the server.

If the DHCP service has to be removed, it can have a significant impact on network users. All client systems require a valid IP address to get onto the network. If DHCP is unavailable, each client system would need to be configured with a static IP address. Because DHCP IP addressing is automatic and does not assign duplicate IP addresses, as sometimes happens with manual entries, DHCP is the preferred method of network IP assignment.

If DHCP is added to a network, all client systems will need to be configured to use DHCP. In a Windows environment, this is as easy as selecting a radio button to use DHCP. If client systems are not configured to use the DHCP server, they will not be able to access the network.