实验一：EIGRP度量值计算(参考配置).doc

WWW.XUEXIZU.COM实验一：EIGRP度量值计算实验目标：观察EIGRP度量值的计算实验TOP： 实验要求：1. 全网运行EIGRP协议2. 所有路由器起一个loopback接口3. 网络收敛后，对路由表中的D路由手动计算其度量值，并与路由条目中的值对比，看是否吻合基本配置R1!hostname R1!no ip domain lookup!interface Loopback0 ip address 55!interface Serial1/0 ip address !interface Serial2/0 ip address !R2!hostname R2!no ip domain lookup!interface Loopback0 ip address 55!interface Serial2/0 ip address !R3!hostname R3!no ip domain lookup!interface Loopback0 ip address 55!interface Serial1/0 ip address !批注：路由器接口默认是关闭的，所以应将对应的接口开启如上配置，已经将基本的地址信息配置完成，下面启动基本的EIGRPR1(config)#router eigrp 100R1(config-router)#network 55 R1(config-router)#network 55R1(config-router)#network R1(config-router)#no auto-summaryR2(config)#router eigrp 100R2(config-router)#network R2(config-router)#network 55R2(config-router)#no auto-summary R3(config)#router eigrp 100R3(config-router)#network 55R3(config-router)#network R3(config-router)#no auto-summary验证：我们可以通过show ip eigrp neighbors 命令来验证本路由器与其他路由器之间的邻居关系是否正常建立，以R1为例R1#show ip eigrp neighbors IP-EIGRP neighbors for process 100H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num1 Se2/0 13 00:01:06 40 240 0 20 Se1/0 12 00:01:27 38 228 0 3R1#/说明R1与R2和R3之间的邻居关系正常建立现在我们查看R1是否已经学习到R2和R3的路由条目，通过show ip route命令可以看出路由器是否学习到邻居的路由，以R1为例R1#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 routeGateway of last resort is not set /32 is subnetted, 1 subnetsC is directly connected, Loopback0 /32 is subnetted, 1 subnetsD 90/2297856 via , 00:07:38, Serial1/0 /32 is subnetted, 1 subnetsD 90/2297856 via , 00:07:15, Serial2/0 /24 is subnetted, 1 subnetsC is directly connected, Serial1/0 /24 is subnetted, 1 subnetsC is directly connected, Serial2/0R1#通过如上信息我们可以看出本路由器现在已经学习到R2和R3的LOOPBACK接口信息，我们发现学习到的路由条目（以从R2学习到的路由为例），我们发现学习到R2的路由在R1的路由表中的表现形式是D 90/2297856 via , 00:07:38, Serial1/0注意到中括号中的信息，我们发现R1学习到/32的路由在路由表中的AD值（即管理距离值）是90，而开销值是2297856。我们知道EIGRP对于从本EIGRP域内学习到的路由，她的AD值均为90，只有学习到外部域（即非EIGRP域）的路由时，AD才会变化，对学习到的外部路由在路由表中的AD值为170（这一部分在后面的EIGRP重发布中讲解）。对于后面的开销值，EIGRP的开销值计算时依据以下公式得来：Metric=K1*BW+K2*BW/（256-LOAD）+K3*DLY*K5/（RELIABILITY+K4）*256在这里，BW是沿着路由路径到达目的网段的所有出战接口的BW带宽中的最小值，而DLY是这条路径DLY延迟的总和。系数K1到K5是可配置的加权值，它们的默认值是：K1=K3=1，K2=K4=K5=0。可以通过下面的命令来更改：metric weights tos k1 k2 k3 k4 k5批注：BW是用因子107Kbit除以带宽得来的，DLY是以10usec作为最小计量单位如果K5被设置为0，则K5/（RELIABILITY+K4）这一项将不适用。按默认的给定加权值的缺省值，EIGRP的复合度量的计算公式将简化成缺省的度量（默认路由器使用的度量）：Metric=K1*BW +K3*DLY*256我们可以通过show ip protocols命令来查看给定加权值的缺省值，以R1为例R1#show ip protocols Routing Protocol is eigrp 100 Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Default networks flagged in outgoing updates Default networks accepted from incoming updates EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0 EIGRP maximum hopcount 100 EIGRP maximum metric variance 1 Redistributing: eigrp 100 EIGRP NSF-aware route hold timer is 240s Automatic network summarization is not in effect Maximum path: 4 Routing for Networks: /32 /24 /24 Routing Information Sources: Gateway Distance Last Update 90 00:42:52 90 00:42:54 Distance: internal 90 external 170R1#/此时，我们按照默认给定的加权值来计算R1学习R2的环回接口的开销：【1】 BW，是沿着路由路径到达目的网段的所有出战接口的BW带宽中的最小值我们从TOP中可以看出，R1到达R2的LO0接口需要经过R1自身的S1/0和R2的LO0，我们可以通过show interfaces来查看这两个接口的BWR1#show interfaces Serial 1/0Serial1/0 is up, line protocol is up Hardware is M4T Internet address is /24 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation HDLC, crc 16, loopback not set Keepalive set (10 sec) Restart-Delay is 0 secs Last input 00:00:03, output 00:00:00, output hang never Last clearing of show interface counters 01:08:06 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: weighted fair Output queue: 0/1000/64/0 (size/max total/threshold/drops) Conversations 0/1/256 (active/max active/max total) Reserved Conversations 0/0 (allocated/max allocated) Available Bandwidth 1158 kilobits/sec 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 1023 packets input, 66556 bytes, 0 no buffer Received 361 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 1041 packets output, 68118 bytes, 0 underruns 0 output errors, 0 collisions, 5 interface resets 0 output buffer failures, 0 output buffers swapped out 4 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=upR1#R2#show interfaces loopback 0Loopback0 is up, line protocol is up Hardware is Loopback Internet address is /32 MTU 1514 bytes, BW 8000000 Kbit, DLY 5000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation LOOPBACK, loopback not set Last input 00:00:03, output never, output hang never Last clearing of show interface counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/0 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 646 packets output, 38760 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 output buffer failures, 0 output buffers swapped outR2#通过黄色背景的字体，我们知道两个出口的带宽分别是R1的S1/0为1.544M，而R2的LO0为8000M，所以R1去往R2LO0接口的BW应该按照最小的BW即R1S1/0接口的BW计算，BW=1.544M【2】查看R1和R2的输出信息中的红色字体，我们得出DLY=20000+5000=25000 usec这时我们得出R1去往R2LO0接口所在的网段即/32，需要的开销值为Metric=1*BW +1*DLY*256即Metric=1*107Kbit/1544Kbit +1*(20000usec+5000usec)/10usec*256=6476+2500*256=2297856批注：对于BW，BW=107/1544=6476.6839，这里我对其取整即按照整数对其处理，那么BW=6476计算结果与实验得出的路由表中的结果是符合的补充： 既然默认情况下，路由器计算Metric值是以BW和DLY为参考标准，以下我们修改这些标准，以BW为例我们可以通过在接口下修改接口带宽来实现对BW的影响，以R1为例即通过命令R1(config)#int s1/0R1(config-if)#bandwidth ? Bandwidth in kilobits inherit Specify how bandwidth is inheritedR1(config-if)#bandwidth 10000/我们此时将R1的S1/0接口的带宽设置为10000Kbit即10M此时，我们查看一下R1的S1/0R1#show interfaces s1/0Serial1/0 is up, line protocol is up Hardware is M4T Internet address is /24 MTU 1500 bytes, BW 10000 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation HDLC, crc 16, loopback not set Keepalive set (10 sec) Restart-Delay is 0 secs Last input 00:00:01, output 00:00:00, output hang never Last clearing of show interface counters 02:21:16 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: weighted fair Output queue: 0/1000/64/0 (size/max total/threshold/drops) Conversations 0/1/256 (active/max active/max total) Reserved Conversations 0/0 (allocated/max allocated) Available Bandwidth 7500 kilobits/sec 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 2502 packets input, 160688 bytes, 0 no buffer Received 874 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 2520 packets output, 162075 bytes, 0 underruns 0 output errors, 0 collisions, 5 interface resets 0 output buffer failures, 0 output buffers swapped out 4 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=upR1#/我们看到R1的S1/0接口的带宽有1544Kbit变化为10000Kbit这时，我们再去查看R1的路由表R1#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