Reserved Addresses and Lease Type

Addresses can be reserved by manually assigning them to particular clients. A reserved address can have a permanent or dynamic lease associated with it. When a reserved address is assigned a permanent lease, the address can only be allocated to the client that is bound to the address, the DHCP server cannot allocate the address to another client, and the address cannot be reclaimed by the DHCP server.

If a reserved address is assigned a dynamic lease, the address can only be allocated to the client that is bound to the address, but the client must track lease time and negotiate for a lease extension as if the address were not reserved. This allows you to track when the client is using the address by looking at the network table.

You cannot create reserved addresses for all the IP addresses during the initial configuration because they are intended to be used sparingly for individual addresses.