Dynamic Host Configuration Protocol (DHCP)

What DHCP is

DHCP was established to relieve the administrative burden of assigning and maintaining IP address information for internetwork connections. DHCP provides automatic and reliable TCP/IP network configuration, and ensures that address conflicts do not occur.

How DHCP Works

When a client computer needs to start up TCP/IP operations, it broadcasts a request for IP address information. The DHCP Server assigns a new IP address and sends this to the client together with the lease duration, address of the client's gateway and the subnet mask for the network that the client is on. This information is acknowledged by the client and used to set up its network configuration. It eliminates much of the work required to set up clients manually and reduces the number of user errors caused by unfamiliarity with networking parameters. To guarantee non-duplication of IP addresses, each time a server issues an IP address it writes this information to non-volatile memory.

The DHCP administrator specifies which IP addresses are assigned, the maximum duration of leases, and all configuration parameters that are available to clients through DHCP. Most Windows clients renew their leases midway through the lease duration. An IP address is available for reallocation once its lease has expired without renewal. A client moving from one subnet to another must request a new IP address on the new subnet.

Participating in the DHCP Service

Please follow the DHCP request procedure. IT Admins should gather the following items before proceeding:

  • Range of IP addresses to be used for DHCP address assignment; it's preferred, but not necessary that the range of addresses be contiguous.
  • Required lease duration, CCS recommends a  lease of eight hours.
  • Range of static IP addresses to be reserved for printers and servers.

Please note: The DHCP service covers the entire campus and provides DHCP/BOOTP to many subnets and buildings. For this reason, it is very important that you contact the CCS Help Centre (x58888) before turning on DHCP services for your new NetWare and Windows NT file servers. Starting up a DHCP service while connected to the campus network can cause problems for other network users in your building.