Dynamic Host Configuration Protocol

Enables a computer with a DHCP client to dynamically obtain an IP address for a fixed length of time from a remote server .  The lease period can range from 1 minute to 99 years, but Missouri State University uses 3 or 7 days.  When the lease period expires, the server can assign the IP address to another client on the network.  DHCP also enables clients to acquire the IP configuration parameters they need to communicate on a network, such as default gateway address, subnet mask, DNS addresses, and WINS addresses.

Missouri State University has two time periods for which DHCP leases are kept.  For users who have already been converted to the new VLAN configuration, the lease period is seven days.  Users not yet converted  have only a three day lease.   As long as the machine is turned on at least once in within their lease period they will retain their IP Address.  If the number of days has exceeded the lease period the DHCP server will still attempt to assign the machine the same address provided that it has not been taken by another machine in that time period.  This usurping of addresses should only happen if the address space is very full.  Having lots of addresses free is one reason why Missouri State University is readdressing the network.

Properly configured DHCP servers allow users to literally un-box a new computer, plug it into a network outlet, and operate the machine on the network without having to contact anyone.  If the machine needs to be moved around the network environment, simply unplug it and reattach it to the network anywhere.  DHCP will still retain the old lease until normal expiration, but will assign a new lease which is valid for the VLAN or subnet.  The mobility without intervention that this creates is extremely valuable to all users, especially lap top users.