Technical data

• A set of rules for delivering client-specific configuration parameters from a
DHCP server to a client
The server and client communicate to accomplish the following steps:
1. When a DHCP client boots, it broadcasts a DHCP request, asking that any
DHCP server on the network provide it with an IP address and configuration
parameters.
2. A DHCP server on the network that is authorized to configure this client sends
the client a reply that offers an IP address.
3. When the client receives the offer, it can accept it or wait for other offers from
other servers on the network.
4. Once the client accepts an offer, it sends an acceptance message to the server.
5. When the server receives the acceptance message, it sends an acknowledgment
with the offered IP address and any other configuration parameters that the
client requested. (The server only responds to specific client requests; it does
not impose any parameters on the client.)
6. If the dynamic address allocation method is used, the IP address offered to the
client has a specific lease time that determines how long the IP address is valid.
During the lifetime of the lease, the client repeatedly asks the server to renew. If
the client does not renew it, the lease expires.
Once the lease expires, the IP address can be recycled and given to another client.
When the client reboots, it can be given the old address, if available, or it can be
assigned a new address.
For more information about how DHCP operates, refer to RFC 2131 and RFC 1534.
5.3.2 How DHCP Allocates IP Addresses
With TCP/IP Services, DHCP uses dynamic and static IP address-mapping
methods. Table 5–2 describes the allocation methods that service DHCP and
BOOTP-only client requests.
Network Server Services 5–7