Which statement describes the process of dynamically assigning IP addresses by the DHCP server?
A. Addresses are allocated after a negotiation between the server and the host to determine the length of the agreement. B. Addresses are permanently assigned so that the hosts uses the same address at all times. C. Addresses are assigned for a fixed period of time, at the end of the period, a new request for an address must be made. D. Addresses are leased to hosts, which periodically contact the DHCP server to renew the lease.
Correct Answer: D
Explanation: The DHCP lifecycle consists of the following:
Allocation: A client begins with no active lease, and hence, no DHCP-assigned address. It acquires a lease through a process of allocation.
Reallocation: If a client already has an address from an existing lease, then when it reboots or starts up after being shut down, it will contact the DHCP server that granted it the lease to confirm the lease and acquire operating parameters. This is sometimes called reallocation; it is similar to the full allocation process but shorter.
Normal Operation: Once a lease is active, the client functions normally, using its assigned IP address and other parameters during the “main part” of the lease. The client is said to be bound to the lease and the address.
Renewal: After a certain portion of the lease time has expired, the client will attempt to contact the server that initially granted the lease, to renew the lease so it can keep using its IP address.
Rebinding. If renewal with the original leasing server fails (because, for example, the server has been taken offline), then the client will try to rebind to any active DHCP server, trying to extend its current lease with any server that will allow it to do so.
Release: The client may decide at any time that it no longer wishes to use the IP address it was assigned, and may terminate the lease, releasing the IP address.