【71-75】Traditional network layer packet forwarding relies on the information provided by network layer（71）protocols，or static routing，to make an independent forwarding decision at each（72）within the network．the forwarding decision is based solely on the destination（73）IP address．all packets for the same destination follow the same path across the network if no other equal-cost（74）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 GatewayRouting Protocol（EIGRP）also supports non-equal-cost（75）sharing although the default behavior of this protocol is equal-cost．you must configure EIGRP variance for non-equal-cost load balancing．
