时间：2006年2月11日13:45-14:15
时间花费 总计约0.5小时
实验设备：2501 3台
实验拓扑：

需求：配置EIGRP负载均衡，实现R3 R5之间的不等成本链路的负载均衡

参考资料：
Deploying IGRP/EIGRP
值得记录的信息：
EIGRP配置结束之后可以看到下面的信息（此时还没有敲variance命令，也就是说还没有允许使用负载均衡）。
R3#sh ip eigrp top
IP-EIGRP Topology Table for AS(64)/ID(1.1.1.1)
Codes: P – Passive, A – Active, U – Update, Q – Query, R – Reply,
r – reply Status, s – sia Status
P 9.9.9.9/32, 1 successors, FD is 2323456
via 14.1.1.2 (2323456/2297856), Ethernet0
via 1.1.1.2 (2809856/2297856), Serial1
此时eigrp拓扑表里面已经有了2条
R3: show ip route
…
9.0.0.0/32 is subnetted, 1 subnets
D 9.9.9.9 [90/2323456] via 14.1.1.2, 00:02:34, Ethernet0
…
但是由于此时只有最优路径装入路由表，因此sh ip route值能看到这一条
使用variance 2之后show ip route可以看到：
…
D 9.9.9.9 [90/2323456] via 14.1.1.2, 00:00:13, Ethernet0
[90/2809856] via 1.1.1.2, 00:00:13, Serial1
…
R3#sh ip route 9.9.9.9
Routing entry for 9.9.9.9/32
Known via “eigrp 64”, distance 90, metric 2323456, type internal
Redistributing via eigrp 64
Last update from 1.1.1.2 on Serial1, 00:01:23 ago
Routing Descriptor Blocks:
* 14.1.1.2, from 14.1.1.2, 00:01:23 ago, via Ethernet0
Route metric is 2323456, traffic share count is 40
Total delay is 26000 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 2
1.1.1.2, from 1.1.1.2, 00:01:23 ago, via Serial1
Route metric is 2809856, traffic share count is 33
Total delay is 45000 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 2
此时*所在的位置表示使用14.1.1.2作为传送路径，traffic share count表示传送了40个包后会切换到另外一条路径
ping了50个包之后再次执行sh ip route 9.9.9.9可以看到
R3#sh ip route 9.9.9.9
Routing entry for 9.9.9.9/32
Known via “eigrp 64”, distance 90, metric 2323456, type internal
Redistributing via eigrp 64
Last update from 1.1.1.2 on Serial1, 00:02:45 ago
Routing Descriptor Blocks:
14.1.1.2, from 14.1.1.2, 00:02:45 ago, via Ethernet0
Route metric is 2323456, traffic share count is 40
Total delay is 26000 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 2
* 1.1.1.2, from 1.1.1.2, 00:02:45 ago, via Serial1
Route metric is 2809856, traffic share count is 33
Total delay is 45000 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 2
此时*标记在1.1.1.2处
进入router eigrp 64后可以执行下面两个命令：
traffic-share balanced
traffic-share min across-interfaces
第一个命令表示在使用负载均衡，第二个命令表示只在最优路径上使用负载均衡（如果多条最优路径的metric正好一样）。需要注意的是在使用第二条命令的时候不会影响路由表条目！
比如使用了traffic-share min across-interfaces之后shown ip route可以得到下面的结果
…
D 9.9.9.9 [90/2323456] via 14.1.1.2, 00:02:45, Ethernet0
[90/2809856] via 1.1.1.2, 00:02:45, Serial1
…
看明细路由则会发现非最优路径的traffic share count是0。
R3#sh ip route 9.9.9.9
Routing entry for 9.9.9.9/32
Known via “eigrp 64”, distance 90, metric 2323456, type internal
Redistributing via eigrp 64
Last update from 1.1.1.2 on Serial1, 00:00:22 ago
Routing Descriptor Blocks:
* 14.1.1.2, from 14.1.1.2, 00:00:22 ago, via Ethernet0
Route metric is 2323456, traffic share count is 1
Total delay is 26000 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 2
1.1.1.2, from 1.1.1.2, 00:00:22 ago, via Serial1
Route metric is 2809856, traffic share count is 0
Total delay is 45000 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 2