学习
实践
活动
专区
工具
TVP
写文章

EIGRP非等价负载均衡-每天15分钟回顾China-CCIE,玩转网络技术

24

第24篇:EIGRP非等价负载均衡

上一节我们学习了EIGRP基础实验,今天我们开始学习EIGRP非等价负载均衡跟着我一起往下看吧。

配置EIGRP实验

说明:实验配置共包含:

EIGRP基础实验

EIGRP非等价负载均衡

EIGRP Stub

EIGRP手工汇总

EIGRP认证

EIGRP默认路由

基于上节的基础实验配置,本节我们延续上节的实验环境进一步学习EIGRP的非等价负载均衡。

4.测试EIGRP非等价负载均衡

(1)查看R1到目标4.4.4.4的RD:

r1#show ip eigrp topology

IP-EIGRP Topology Table for AS(1)/ID(13.1.1.1)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

r - reply Status, s - sia Status

P 4.4.4.0/24, 1 successors, FD is 158720

via 12.1.1.2 (158720/156160), FastEthernet0/1

P 12.1.1.0/24, 1 successors, FD is 28160

via Connected, FastEthernet0/1

P 13.1.1.0/24, 1 successors, FD is 2562560

via Connected, FastEthernet0/0

via 12.1.1.2 (2177536/2174976), FastEthernet0/1

P 24.1.1.0/24, 1 successors, FD is 30720

via 12.1.1.2 (30720/28160), FastEthernet0/1

P 34.1.1.0/24, 1 successors, FD is 2174976

via 12.1.1.2 (2174976/2172416), FastEthernet0/1

via 13.1.1.3 (3074560/2169856), FastEthernet0/0

r1#

说明:因为R1与R2是EIGRP邻居,R2将路由信息发给R1之后,R2到目标4.4.4.4的Metric值156160就成为了R1到目标4.4.4.4的RD值,而当前R1到目标4.4.4.4的FD为158720,这条信息将被放入路由表中使用;拓朴数据库中显示确实如此;而拓朴数据库中为什么没有R1经过R3到目标4.4.4.4的路径,下面来查看:

(2)查看R1经过R3到目标4.4.4.4的路径:

说明:R1经过R3到目标4.4.4.4的路径不能存放于拓朴数据库中,应该是不满足FC的条件(R3到目标4.4.4.4的Metric值必须小于R1当前的FD值158720)

所以,我们手工计算R3到目标4.4.4.4的Metric值

查看带宽与延迟:

r4#sh interfaces loopback 0

Loopback0 is up, line protocol is up

Hardware is Loopback

Internet address is 4.4.4.4/24

MTU 1514 bytes, BW 8000000 Kbit, DLY 5000 usec,

r3#sh int s1/0

Serial1/0 is up, line protocol is up

Hardware is M4T

Internet address is 34.1.1.3/24

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec

R3到4.4.4.4链路中的最小带宽为1544 Kbit,延迟之和为20000 usec +5000 usec=25000 usec

应用到公式中为:

(1000 0000/1544 +25000/10)×256

(6476.6 + 2500)×256=2297856

说明:所以很明显,R3到目标4.4.4.4的Metric值必须小2297856大于R1当前的FD值158720,所以无法存放于拓朴数据库中,所以当前R1只使用经过R2到目标4.4.4.4的路径,如下:

r1#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

34.0.0.0/24 is subnetted, 1 subnets

D 34.1.1.0 [90/2174976] via 12.1.1.2, 00:07:46, FastEthernet0/1

4.0.0.0/24 is subnetted, 1 subnets

D 4.4.4.0 [90/158720] via 12.1.1.2, 00:15:36, FastEthernet0/1

24.0.0.0/24 is subnetted, 1 subnets

D 24.1.1.0 [90/30720] via 12.1.1.2, 00:19:50, FastEthernet0/1

12.0.0.0/24 is subnetted, 1 subnets

C 12.1.1.0 is directly connected, FastEthernet0/1

13.0.0.0/24 is subnetted, 1 subnets

C 13.1.1.0 is directly connected, FastEthernet0/0

r1#

★查看R3到目标4.4.4.4的路径:

r3#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

34.0.0.0/24 is subnetted, 1 subnets

C 34.1.1.0 is directly connected, Serial1/0

4.0.0.0/24 is subnetted, 1 subnets

D 4.4.4.0 [90/161280] via 13.1.1.1, 00:13:15, FastEthernet0/0

24.0.0.0/24 is subnetted, 1 subnets

D 24.1.1.0 [90/33280] via 13.1.1.1, 00:13:15, FastEthernet0/0

12.0.0.0/24 is subnetted, 1 subnets

D 12.1.1.0 [90/30720] via 13.1.1.1, 00:13:15, FastEthernet0/0

13.0.0.0/24 is subnetted, 1 subnets

C 13.1.1.0 is directly connected, FastEthernet0/0

r3#

说明:由于R3从S1/0到目标4.4.4.4的Metric值太大,所以R3自己都没从S1/0到4.4.4.4,而选择从R1到4.4.4.4。

(3)计算R3成为R1到目标4.4.4.4的FS的条件:

因为R1当前的FD为158720,所以R3到目标4.4.4.4的Metric值必须小于158720,才能成为FS,因为R3的出口S1/0为帧中继接口,带宽实在太低,即使没有延迟,也不能成为FS,所以我们事先将接口带宽改为100 000 Kbit/s,从而再修改延迟到相应值,延迟需要改成多少,需要将公式进行反运算:

公式为:

R4 loopback 0的延迟为5000 usec,设置总延迟为X,则:

(1000 0000 / 100 000 + X)× 256 = 158720

(100 + X)=158720 /256

(100 + X)= 620

X=520

所以R3成为R1到目标4.4.4.4的FS的条件的总延迟必须小于520,等于520也不行,

因为延迟除以10得到520,所以原始延迟为5200,而R4 loopback 0的延迟为5000 usec,得R3 S1/0的延迟为200,为了取小一点的值,我们取190,下面配置R3 S1/0的接口延迟为190:

r3(config)#int s1/0

r3(config-if)#delay 19

说明:在配置时,会自动乘以10,所以要配置190,就配置19。

(4)查看R3修改接口延迟后的情况:

r3#sh int s1/0

Serial1/0 is up, line protocol is up

Hardware is M4T

Internet address is 34.1.1.3/24

MTU 1500 bytes, BW 100000 Kbit, DLY 190 usec,

说明:延迟已经改成预计的190了。

(5)查看R3到目标4.4.4.4的情况:

r3#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

34.0.0.0/24 is subnetted, 1 subnets

C 34.1.1.0 is directly connected, Serial1/0

4.0.0.0/24 is subnetted, 1 subnets

D 4.4.4.0 [90/158464] via 34.1.1.4, 00:00:53, Serial1/0

24.0.0.0/24 is subnetted, 1 subnets

D 24.1.1.0 [90/33024] via 34.1.1.4, 00:00:53, Serial1/0

12.0.0.0/24 is subnetted, 1 subnets

D 12.1.1.0 [90/30720] via 13.1.1.1, 00:00:53, FastEthernet0/0

13.0.0.0/24 is subnetted, 1 subnets

C 13.1.1.0 is directly connected, FastEthernet0/0

r3#

说明:R3已经选择从S1/0到4.4.4.4,说明改动有效果。

(6)查看R1拓朴数据库中到目标4.4.4.4的情况:

r1#sh ip eigrp topology

IP-EIGRP Topology Table for AS(1)/ID(13.1.1.1)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

r - reply Status, s - sia Status

P 4.4.4.0/24, 1 successors, FD is 158720

via 12.1.1.2 (158720/156160), FastEthernet0/1

via 13.1.1.3 (161024/158464), FastEthernet0/0

P 12.1.1.0/24, 1 successors, FD is 28160

via Connected, FastEthernet0/1

P 13.1.1.0/24, 1 successors, FD is 28160

via Connected, FastEthernet0/0

P 24.1.1.0/24, 1 successors, FD is 30720

via 12.1.1.2 (30720/28160), FastEthernet0/1

P 34.1.1.0/24, 1 successors, FD is 33024

via 13.1.1.3 (33024/30464), FastEthernet0/0

r1#

说明:R1当前的拓朴数据库中同时存在R2和R3到达目标4.4.4.4,并且显示经过R2的路径为FD,值为158720,而经过R3的Metric为161024,明显比FD大,但很微小。

(7)通过修改variance值使R1到目标4.4.4.4执行非等价负载均衡

r1(config)#router eigrp 1

r1(config-router)#variance 2

说明:因为当前FD为158720,要包含161024,只需要将FD为158720扩大2倍即可,值为158720×2=317440。

(8)查看R1负载均衡路由表:

r1#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

34.0.0.0/24 is subnetted, 1 subnets

D 34.1.1.0 [90/33024] via 13.1.1.3, 00:00:21, FastEthernet0/0

4.0.0.0/24 is subnetted, 1 subnets

D 4.4.4.0 [90/161024] via 13.1.1.3, 00:00:21, FastEthernet0/0

[90/158720] via 12.1.1.2, 00:00:21, FastEthernet0/1

24.0.0.0/24 is subnetted, 1 subnets

D 24.1.1.0 [90/30720] via 12.1.1.2, 00:00:21, FastEthernet0/1

12.0.0.0/24 is subnetted, 1 subnets

C 12.1.1.0 is directly connected, FastEthernet0/1

13.0.0.0/24 is subnetted, 1 subnets

C 13.1.1.0 is directly connected, FastEthernet0/0

r1#

说明:R1已经执行到4.4.4.4的负载均衡。

(9)测试负载均衡:

r1#traceroute 4.4.4.4

Type escape sequence to abort.

Tracing the route to 4.4.4.4

1 13.1.1.3 92 msec

12.1.1.2 144 msec

13.1.1.3 156 msec

2 24.1.1.4 92 msec

34.1.1.4 112 msec *

r1#

说明:R1已经执行到4.4.4.4的负载均衡。

(10)查看邻居发送的路由条目:

说明:当EIGRP用于复杂大型网络时,有时需要查看从邻居收到的路由条目情况。

r1#sh ip eigrp 1 accounting

IP-EIGRP accounting for AS(1)/ID(13.1.1.1)

Total Prefix Count: 5 States: A-Adjacency, P-Pending, D-Down

State Address/Source Interface Prefix Restart Restart/

Count Count Reset(s)

A 13.1.1.3 Fa0/0 3 0 0

A 12.1.1.2 Fa0/1 2 0 0

r1#

说明:R1从13.1.1.3(R3)收到3条,从12.1.1.2(R2)收到2条。

好了,今天这15分钟也完成了,建议线下动手做下实验,下一节我们将学习EIGRP Stub

  • 发表于:
  • 原文链接http://kuaibao.qq.com/s/20180324G1FGFA00?refer=cp_1026
  • 腾讯「腾讯云开发者社区」是腾讯内容开放平台帐号(企鹅号)传播渠道之一,根据《腾讯内容开放平台服务协议》转载发布内容。
  • 如有侵权,请联系 cloudcommunity@tencent.com 删除。

关注

腾讯云开发者公众号
10元无门槛代金券
洞察腾讯核心技术
剖析业界实践案例
腾讯云开发者公众号二维码

扫码关注腾讯云开发者

领取腾讯云代金券