DHCP in Large Networks

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For an enterprise network, you should:

  • Plan the physical subnets of the network and relative placement of DHCP servers. This includes planning for placement of DHCP (and WINS) servers among subnets in a way that reduces b-node broadcasts across routers.

  • Specify the DHCP option types and their values to be predefined per scope for the DHCP clients. This can include planning for scopes based on the needs of particular groups of users. For example, for a unit that frequently moves computers to different locations, shorter lease durations can be defined for the related scopes. This approach collects IP addresses that are changed frequently and disposed of, and returns them to the pool of available addresses that can be used for new lease offerings.

  • Recognize the impact that slower links have on your WAN environment. Place DHCP, WINS, and DNS servers to maximize response time and minimize low-speed traffic.

As one example of planning for a large enterprise network, the segmenting of the WAN into logical subnets can match the physical structure of the internetwork. Then one IP subnet can serve as the backbone, and off this backbone each physical subnet maintains a separate IP subnet address.