先看一下路由器的基本配置情况：
routerA：
interface Loopback0
ip address 10.1.1.1 255.255.255.0
!
interface FastEthernet0/0
ip address 152.1.1.1 255.255.255.0
duplex auto
speed auto
!
interface Serial1/0
ip address 192.1.1.1 255.255.255.0
serial restart-delay 0
!
router eigrp 10
network 10.0.0.0
network 152.1.0.0
network 192.1.1.0
no auto-summary
routerB：
interface FastEthernet0/0
ip address 152.1.1.2 255.255.255.0
duplex auto
speed auto
!
interface Serial1/0
ip address 192.1.1.2 255.255.255.0
serial restart-delay 0
!
interface Serial1/2
ip address 193.1.1.2 255.255.255.0
serial restart-delay 0
router eigrp 10
network 192.1.1.0
network 193.1.1.0
no auto-summary
routerC：
interface Loopback0
ip address 3.3.3.3 255.255.255.0
!
interface Serial1/2
ip address 193.1.1.3 255.255.255.0
serial restart-delay 0
router eigrp 10
network 3.0.0.0
network 193.1.1.0
no auto-summary
看一下路由器A的拓扑表到3.3.3.0有两个路径，因为下面的AD<FD，所以下面的路径为到3.3.3.0的FS
routerA#sh ip eigrp topology detail-links
IP-EIGRP Topology Table for AS(10)/ID(1.1.1.1)
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia Status
P 3.3.3.0/24, 1 successors, FD is 2300416, serno 30, Stats m(152)M(152)A(152)c(1)
via 152.1.1.2 (2300416/2297856), FastEthernet0/0
via 192.1.1.2 (2809856/2297856), Serial1/0
P 152.1.1.0/24, 1 successors, FD is 28160, serno 1
via Connected, FastEthernet0/0
via 192.1.1.2 (2172416/28160), Serial1/0
P 192.1.1.0/24, 1 successors, FD is 2169856, serno 2
via Connected, Serial1/0
via 152.1.1.2 (2172416/2169856), FastEthernet0/0
P 193.1.1.0/24, 1 successors, FD is 2172416, serno 8
via 152.1.1.2 (2172416/2169856), FastEthernet0/0
via 192.1.1.2 (2681856/2169856), Serial1/0
路由表中只有一条路由
routerA#sh ip route 3.3.3.0
Routing entry for 3.3.3.0/24
Known via "eigrp 10", distance 90, metric 2300416, type internal
Redistributing via eigrp 10
Last update from 152.1.1.2 on FastEthernet0/0, 00:08:15 ago
Routing Descriptor Blocks:
* 152.1.1.2, from 152.1.1.2, 00:08:15 ago, via FastEthernet0/0
Route metric is 2300416, traffic share count is 1
Total delay is 25100 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 2
routerA#sh ip rou
routerA#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
152.1.0.0/24 is subnetted, 1 subnets
C 152.1.1.0 is directly connected, FastEthernet0/0
3.0.0.0/24 is subnetted, 1 subnets
D 3.3.3.0 [90/2300416] via 152.1.1.2, 00:08:35, FastEthernet0/0
D 193.1.1.0/24 [90/2172416] via 152.1.1.2, 00:08:35, FastEthernet0/0
C 192.1.1.0/24 is directly connected, Serial1/0
下面添加一条variance命令，取值范围1-128，默认为1。
routerA(config)#router eigrp 10
routerA(config-router)#variance 2
非等价负载均衡路径首先必须是路由的FS，然后FD要小于successor的FD*variance值。当然，最多不能超过6条，默认为4条。
routerA#sh ip route
Gateway of last resort is not set
152.1.0.0/24 is subnetted, 1 subnets
C 152.1.1.0 is directly connected, FastEthernet0/0
3.0.0.0/24 is subnetted, 1 subnets
D 3.3.3.0 [90/2809856] via 192.1.1.2, 00:08:53, Serial1/0
[90/2300416] via 152.1.1.2, 00:08:53, FastEthernet0/0
D 193.1.1.0/24 [90/2681856] via 192.1.1.2, 00:08:53, Serial1/0
[90/2172416] via 152.1.1.2, 00:08:53, FastEthernet0/0
C 192.1.1.0/24 is directly connected, Serial1/0
