The Dynamic Host Configuration Protocol provides configuration parameters to Intenet （ hosts ）. DHCP consists of two components: a （protocol ） for delivering host-specific configuration parameters from a DHCP server to a host and a mechanism for allocation of network addresses to hosts. DHCP is built on a client-server model, where designated DHCP server hosts allocate network addresses and deliver （ configuration ） parameters to dynamically configured hosts. DHCP supports three mechanisms for IP address allocation. In "automatic allocation", DHCP assigns a （permanent ） IP address to a client. In "dynamic allocation", DHCP assigns an IP address to a client for a limited period of time. In "manual allocation", a client's IP address is assigned by the network （ administrator ）, and DHCP is used simply to convey the assitped address to the client.


Traditional network layer packet forwarding relies on the information provided by network layer（ routing）protocols, or static routing, to make an independent forwarding decision at each（ hop）within the network. The forwarding decision is based solely on the destination（customer ）IP address. All packets for the same destination follow the same path across the network if no other equal-cost（paths ）exist. Whenever a router has two equal-cost paths toward a destination, the packets toward the destination might take one or both of them, resulting in some degree of load sharing. Enhanced Interior Gateway Routing Protocol (EIGRP) also supports non-equal-cost（Load）sharing although the default behavior of this protocol is equal-cost. You must configure EIGRP variance for non-equal-cost load balancing.