此实验的目的是为了使从路由器R1到2.2.2.2能够在R1---------R2和R1--------R3------R2这两条路径实现非等价负载均衡。
三个路由器上最基本的接口IP配置略过了，实在是太简单了。
R1：ruter eigrp 10
net 172.16.1.0
net 172.16.2.0
R2：ruter eigrp 10
net 172.16.1.0
net 172.16.3.0
R3: ruter eigrp 10
net 172.16.2.0
net 172.16.3.0
这样配好了，在R1上执行show ip ro
 
D    2.0.0.0/8 [90/2297856] via 172.16.1.2, 00:00:19, Serial1/0
                    172.16.0.0/24 is subnetted, 3 subnets
C       172.16.1.0 is directly connected, Serial1/0
C       172.16.2.0 is directly connected, Serial1/1
D       172.16.3.0 [90/2221056] via 172.16.2.2, 00:07:34, Serial1/1
可是从这里看到的只有一条路径，接着执行show ip eigrp topology all-links
 
 
P 2.0.0.0/8, 1 successors, FD is 2297856
        via 172.16.1.2 (2297856/128256), Serial1/0
        via 172.16.2.2 (23490560/2297856), Serial1/1
P 172.16.1.0/24, 1 successors, FD is 2169856
        via Connected, Serial1/0
P 172.16.2.0/24, 1 successors, FD is 2169856
        via Connected, Serial1/1
P 172.16.3.0/24, 1 successors, FD is 2221056
        via 172.16.2.2 (2221056/307200), Serial1/1
        via 172.16.1.2 (2681856/2169856), Serial1
由于R3通告的到2.2.2.2的AD和SUCCESSOR一样大，所以在用show ip eigrp topology
查看时看不到备份路径，拓扑数据库里放的都是备份路径，而成为备份路径的条件是，路径的通告距离AD必须小于当前路径的SUCCESSOR，通过手动修改R3路由器S1/0接口的带宽和Delay可以使AD小于SUCCESSOR，具体的做法是：
R3：
int s1/0
bandwidth 10000
delay 200
同时还要配置 variance 的值。
router eigrp 10
variance 3
这样配置完成后，再在R1上执行show ip ro,显示这样就表示负载均衡成功了。
 
 
Gateway of last resort is not set
 
D    2.0.0.0/8 [90/2297856] via 172.16.1.2, 00:13:39, Serial1/0
               [90/2349056] via 172.16.2.2, 00:13:39, Serial1/1
     172.16.0.0/24 is subnetted, 3 subnets
C       172.16.1.0 is directly connected, Serial1/0
C       172.16.2.0 is directly connected, Serial1/1
D       172.16.3.0 [90/2221056] via 172.16.2.2, 00:23:02, Serial1/1