EIGRP非等价负载均衡

EIGRP

 

 

拓扑如下:

 

 

路由A实现通往路由C 的lo0接口,启用非等价负载均衡

 

查看路由A的route table

Router#show 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

     10.0.0.0/30 is subnetted, 4 subnets
D       10.3.1.0 [90/6023936] via 10.4.1.2, 00:00:50, Serial1/1
D       10.2.1.0 [90/6023936] via 10.1.1.2, 00:01:00, Serial1/0
C       10.1.1.0 is directly connected, Serial1/0
C       10.4.1.0 is directly connected, Serial1/1
C    192.168.1.0/24 is directly connected, Loopback0
D    192.168.2.0/24 [90/6151936] via 10.4.1.2, 00:00:50, Serial1/1
                    [90/6151936] via 10.1.1.2, 00:00:50, Serial1/0

 

通往192.168.2.0/24的路径有2条 ,而且度量值是相同的 EIGRP自动实现负载均衡

现在把s1/1的bandwidth 改为512，S1/0的bandwidth改为256

Router#show 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

     10.0.0.0/30 is subnetted, 4 subnets
D       10.3.1.0 [90/6023936] via 10.4.1.2, 00:01:26, Serial1/1
D       10.2.1.0 [90/6535936] via 10.4.1.2, 00:01:26, Serial1/1
C       10.1.1.0 is directly connected, Serial1/0
C       10.4.1.0 is directly connected, Serial1/1
C    192.168.1.0/24 is directly connected, Loopback0
D    192.168.2.0/24 [90/6151936] via 10.4.1.2, 00:01:26, Serial1/1

所以现在路由A走S1/1的路

现在设置 Variance值

先看下eigrp拓扑

Router#show ip eigrp topology
IP-EIGRP Topology Table for AS(100)/ID(192.168.1.1)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
       r - reply Status, s - sia Status

P 10.3.1.0/30, 1 successors, FD is 6023936
        via 10.4.1.2 (6023936/5511936), Serial1/1
P 10.2.1.0/30, 1 successors, FD is 6535936
        via 10.4.1.2 (6535936/6023936), Serial1/1, serno 120
        via 10.1.1.2 (11023872/5511936), Serial1/0
P 10.1.1.0/30, 1 successors, FD is 10511872
        via Connected, Serial1/0
        via 10.4.1.2 (7047936/6535936), Serial1/1
P 10.4.1.0/30, 1 successors, FD is 5511936
        via Connected, Serial1/1
P 192.168.1.0/24, 1 successors, FD is 128256
        via Connected, Loopback0
P 192.168.2.0/24, 1 successors, FD is 6151936
        via 10.4.1.2 (6151936/5639936), Serial1/1, serno 111
        via 10.1.1.2 (11151872/5639936), Serial1/0

 

要实现负载均衡FC要满足两个条件：一是首先要成为可继路由,即FC的AD<最优的FD。二是最优FD乘以variance>次优FD

看的出最优FD的值是6151936

若想做可继路由的话 走S1/0的AD必须小于S1的FD

 

即 5639936<= 6151936 

所以S1/0成为可继

若想实现非等价负载 则Variance值= 11151872/6151936=取整(1.81)+1 =2

且6151936*2=12303872 >11151872

Router(config)#router eig
Router(config)#router eigrp 100
Router(config-router)#va
Router(config-router)#variance 2

 

再show下路由表

Router#show ip route
*May 22 21:33:02.671: %SYS-5-CONFIG_I: Configured from console by console
Router#show 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

     10.0.0.0/30 is subnetted, 4 subnets
D       10.3.1.0 [90/6023936] via 10.4.1.2, 00:01:08, Serial1/1
D       10.2.1.0 [90/6535936] via 10.4.1.2, 00:01:08, Serial1/1
                 [90/11023872] via 10.1.1.2, 00:01:08, Serial1/0
C       10.1.1.0 is directly connected, Serial1/0
C       10.4.1.0 is directly connected, Serial1/1
C    192.168.1.0/24 is directly connected, Loopback0
D    192.168.2.0/24 [90/6151936] via 10.4.1.2, 00:01:08, Serial1/1
                    [90/11151872] via 10.1.1.2, 00:01:08, Serial1/0

 

show下去192.168.2.0/24的路由

 

Router#show ip route 192.168.2.1
Routing entry for 192.168.2.0/24
  Known via "eigrp 100", distance 90, metric 6151936, type internal
  Redistributing via eigrp 100
  Last update from 10.1.1.2 on Serial1/0, 00:10:48 ago
  Routing Descriptor Blocks:
  * 10.4.1.2, from 10.4.1.2, 00:10:48 ago, via Serial1/1
      Route metric is 6151936, traffic share count is 20
      Total delay is 45000 microseconds, minimum bandwidth is 512 Kbit
      Reliability 255/255, minimum MTU 1500 bytes
      Loading 1/255, Hops 2
    10.1.1.2, from 10.1.1.2, 00:10:48 ago, via Serial1/0
      Route metric is 11151872, traffic share count is 11
      Total delay is 45000 microseconds, minimum bandwidth is 256 Kbit
      Reliability 255/255, minimum MTU 1500 bytes
      Loading 1/255, Hops 2

如表所知,在S1/1每往192.168.2.0网段发送20个包后,S1/0才往192.168.2.0网段发送11个包

实现了非等价负载均衡

 

 

现在ping 192.168.2.1 repeat 20看下,记得在ping之前 no ip cef 同时debug ip icmp

看下dsc地址是不是分别s1/1或s1/0接口就可以了