/ IProute0.0.0.0 概 RIPver1路由更 RIPver1主機(jī)路 RIP路由更新 RIP觸發(fā)更 RIP單播更 RIP手工匯 RIPver2認(rèn) 概 EIGRP EIGRPStuckInActive 概 ICMP重定向（ICMPRedirect）來告訴對方，讓對方不要再將數(shù)據(jù)包發(fā)向自己，而應(yīng)該發(fā)到其它★1．當(dāng)路由器從某個接口收到數(shù)據(jù)包后，還要將數(shù)據(jù)包從同一個接口發(fā)往目交給R1。r1(config-if)#noshr2(config-if)#ipadd10.1.1.2255.255.255.0r2(config-if)#noshr2(config-if)#ipadd20.1.1.2255.255.255.0r2(config-if)#noshr3(config-if)#ipadd10.1.1.3255.255.255.0r3(config-if)#noshr4(config-if)#ipadd20.1.1.4255.255.255.0r4(config-if)#noshR320.1.1.0ICMPr3#debugipICMPpacketdebuggingisonSending5,100-byteICMPEchosto20.1.1.4,timeoutis2*Mar100:15:39.075:ICMP:redirectrcvdfrom10.1.1.1-for20.1.1.4use*Mar100:15:39.175:ICMP:echoreplyrcvd,src20.1.1.4,dst*Mar100:15:39.291:ICMP:echoreplyrcvd,src20.1.1.4,dst*Mar100:15:39.323:ICMP:echoreplyrcvd,src20.1.1.4,dst*Mar100:15:39.383:ICMP:echoreplyrcvd,src20.1.1.4,dst*Mar100:15:39.403:ICMP:echoreplyrcvd,src20.1.1.4,dst10.1.1.3的數(shù)據(jù)包發(fā)給網(wǎng)關(guān)R1R1F0/0收到數(shù)據(jù)包后，檢查路由表得知需要再接口進(jìn)出，也滿足第二條源和下一跳同網(wǎng)段，所以R1ICMP重定向，數(shù)可以看出，讓R1來轉(zhuǎn)發(fā)數(shù)據(jù)包確實(shí)是無謂舉動。r3#debugipICMPpacketdebuggingisonSending5,100-byteICMPEchosto20.1.1.4,timeoutis2*Mar100:33:41.511:ICMP:echoreplyrcvd,src20.1.1.4,dst*Mar100:33:41.607:ICMP:echoreplyrcvd,src20.1.1.4,dst*Mar100:33:41.663:ICMP:echoreplyrcvd,src20.1.1.4,dst*Mar100:33:41.719:ICMP:echoreplyrcvd,src20.1.1.4,dst*Mar100:33:41.779:ICMP:echoreplyrcvd,src20.1.1.4,dst10.1.1.3r1(config)#intf0/0r1(config-if)#noipredirects以后的版本可以手工開啟ICMP重定向功能。OSI七層模型中的第二層數(shù)據(jù)鏈路層地址和第IP地址，主機(jī)之間要通信，必須封裝效。在這里需要討論的是代理ARP，故介質(zhì)默認(rèn)為以太網(wǎng)。（以MCMC自己的二層鏈路地址就是目標(biāo)的二層鏈路地址，這就是路由器的代理ARP功能。主ARP的路由16R110.1.0.0/16F0/0的直連網(wǎng)段，其中包含r1(config-if)#ipadd10.1.1.1255.255.0.0r1(config-if)#noshr2(config-if)#ipadd10.1.1.2255.255.255.0r2(config-if)#noshR2直連網(wǎng)段10.1.1.0/24，并且通過配置靜態(tài)路由將去往遠(yuǎn)程網(wǎng)段r3(config-if)#ipadd10.1.1.3255.255.255.0r3(config-if)#noshr3(config-if)#ipadd10.1.2.3255.255.255.0r3(config-if)#noshr4(config-if)#ipadd10.1.2.4255.255.255.0r4(config-if)#noshr1#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-ia-IS-ISinterarea,*-candidatedefault,U-per-userstaticrouteo-ODR,P-periodicdownloadedstaticrouteGatewayoflastresortisnot 網(wǎng)段，所以我們不用寫到10.1.2.0/24的靜態(tài)路由。Sending5,100-byteICMPEchosto10.1.2.4,timeoutis2時，直接在本網(wǎng)段廣播請求目標(biāo)二層鏈路地址，這個廣播被R3R3能10.1.2.0/24ARPR3將自己接口的二層鏈路地址數(shù)據(jù)包交給R3處理，最后網(wǎng)絡(luò)通信成功。HardwareisGt96kFE,addressisc000.1370.0001(biac000.1370.0001)Internetaddressis10.1.2.4/24r3#shintHardwareisGt96kFE,addressisc000.1124.0000(biac000.1124.0000)Internetaddressis10.1.1.3/24r1#shProtocolAddress Age(min)HardwareAddrType Internet10.1.1.3 c000.1124.0000ARPAFastEthernet0/0Internet10.1.1.1 -c000.141c.0000ARPAFastEthernet0/0Internet10.1.2.4 c000.1124.0000ARPAFastEthernet0/0會代替目標(biāo)R4回復(fù)源主機(jī)的二層鏈路地址請求。r2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-ia-IS-ISinterarea,*-candidatedefault,U-per-userstaticrouteo-ODR,P-periodicdownloadedstaticrouteGatewayoflastresortisnot 10.1.1.0isdirectlyconnected,FastEthernet0/0r2#r2#ping10.1.2.4Sending5,100-byteICMPEchosto10.1.2.4,timeoutis2說明：因?yàn)镽210.1.2.0/24為直連網(wǎng)段，所以同上原因，因?yàn)镽3ARP的功能，最后與10.1.2.0/24的網(wǎng)絡(luò)通信正常。Sending5,100-byteICMPEchosto10.1.2.4,timeoutis2Successrateis0percent(0/5)r1#shProtocolAddress Age(min)HardwareAddrType Internet10.1.1.3 c000.1124.0000ARPAFastEthernet0/0Internet10.1.1.1 -c000.141c.0000ARPAFastEthernet0/0Internet10.1.2.4 說明：R3ARP功能后，R110.1.2.0/24通信，R1認(rèn)為目標(biāo)與自己直連，所以會在直連網(wǎng)段直接請求目標(biāo)的二層鏈路地址，錄為plete，最終與10.1.2.0/24的通信以失敗告結(jié)。Sending5,100-byteICMPEchosto10.1.2.4,timeoutis2Successrateis0percent(0/5)r2#shProtocolAddress Age(min)HardwareAddrType Internet10.1.1.2 -c000.13e8.0000ARPAFastEthernet0/0Internet10.1.1.3 c000.1124.0000ARPAFastEthernet0/0Internet10.1.2.4 說明：雖然R210.1.2.0/24的靜態(tài)路由，但因?yàn)殪o態(tài)路由指定去往目標(biāo)為R2與R1一樣，不能與10.1.2.0/24通信。r2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-ia-IS-ISinterarea,*-candidatedefault,U-per-userstaticrouteo-ODR,P-periodicdownloadedstaticrouteGatewayoflastresortisnot10.0.0.0/24issubnetted,2subnets 10.1.2.0[1/0]via10.1.1.3 10.1.1.3（R3R210.1.2.0/2410.1.2.0/24通信Sending5,100-byteICMPEchosto10.1.2.4,timeoutis2說明：更改靜態(tài)路由到達(dá)目標(biāo)網(wǎng)絡(luò)為下一跳地址后，R210.1.2.4的二層鏈路地址，而是改為請求下一跳地址的二層鏈路地址，因?yàn)檎埱蟮牡刂?0.1.1.3，所以R3作出了回應(yīng)，最后R2與目標(biāo)通信成功。則可能因?yàn)橄乱惶酚善麝P(guān)閉了代理ARP而造成通信失敗，但靜態(tài)路由指定為下一IProute0.0.0.0IProute0.0.0.0IPDefault-Network器也需要像PC一樣配置網(wǎng)關(guān)，將所有未知目標(biāo)地址的數(shù)據(jù)包全部交給網(wǎng)關(guān)。routing說明：必須先關(guān)閉路由功能（命令noip10.1.1.1（R1R3上查看默認(rèn)網(wǎng)關(guān)r3#ship LastUse TotalUsesInterfaceICMPredirectcacheisempty測試網(wǎng)絡(luò)連通性r3#pingSending5,100-byteICMPEchosto172.16.1.1,timeoutis2r3#pingSending5,100-byteICMPEchosto192.168.1.1,timeoutis2IProute0.0.0.0為路由器配置默認(rèn)網(wǎng)關(guān)時，IPDefault-Gateway只能在關(guān)閉路由功能后起作用，在路由功能開啟的情況下，通過命令I(lǐng)Proute0.0.0.00.0.0.0同樣可以為路由器配置兩者的區(qū)別在于，IPDefault-Gateway只能在路由功能關(guān)閉時工作，并且一臺路IProute0.0.0.00.0.0.0可以在路由功能開啟時工作，一條路由器可以配置多條IProute0.0.0.00.0.0.0。r3(config)#iproute0.0.0.00.0.0.010.1.1.1（R1r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic 20.1.1.0isdirectlyconnected,FastEthernet0/110.0.0.0/24issubnetted,1subnets S*0.0.0.0/0[1/0]via測試網(wǎng)絡(luò)連通性r3#pingSending5,100-byteICMPEchosto192.168.1.1,timeoutis2r3#pingSending5,100-byteICMPEchosto172.16.1.1,timeoutis2r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-ia-IS-ISinterarea,*-candidatedefault,U-per-userstaticrouteo-ODR,P-periodicdownloadedstaticroute 20.1.1.0isdirectlyconnected,FastEthernet0/110.0.0.0/24issubnetted,1subnets S*0.0.0.0/0[1/0]via[1/0]via網(wǎng)絡(luò)將成為路由器的默認(rèn)網(wǎng)關(guān)，所有未知目標(biāo)的數(shù)據(jù)包全部發(fā)往該網(wǎng)絡(luò)，IP和IS-IS不會傳遞。指出IOS版本號。r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot 20.1.1.0isdirectlyconnected,FastEthernet0/110.0.0.0/24issubnetted,1subnets r3#pingSending5,100-byteICMPEchosto192.168.1.1,timeoutis2r3#pingSending5,100-byteICMPEchosto172.16.1.1,timeoutis2Successrateis0percent(0/5)因?yàn)槁酚杀碇兄挥腥ネ?92.168.1.0/24的靜態(tài)路由，所以R3r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic 20.1.1.0isdirectlyconnected,FastEthernet0/110.0.0.0/24issubnetted,1subnets S*192.168.1.0/24[1/0]via10.1.1.1r3#pingSending5,100-byteICMPEchosto192.168.1.1,timeoutis2r3#pingSending5,100-byteICMPEchosto172.16.1.1,timeoutis2172.16.1.0/24通信。r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic 20.1.1.0isdirectlyconnected,FastEthernet0/1172.16.0.0/16isvariablysubnetted,2subnets,2masks 172.16.1.0/24[1/0]via10.1.1.1 S*192.168.1.0/24[1/0]via10.1.1.1從結(jié)果中看出，172.16.1.0/24并沒有成為默認(rèn)網(wǎng)關(guān)，原因是，ip修改172.16.0.0/16為默認(rèn)網(wǎng)關(guān)：r3(config)#noipdefault-network172.16.1.0說明：增加靜態(tài)路由172.16.0.0/16，并指定為默認(rèn)網(wǎng)關(guān)，需要說明的是，ipdefault-network所指定的網(wǎng)段必須在路由表中真實(shí)存在，所以當(dāng)前必須手工指定到172.16.0.0/16的靜態(tài)路由。r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic *172.16.0.0/16isvariablysubnetted,2subnets,2 S*192.168.1.0/24[1/0]via10.1.1.1ipdefault-networkAD值的被使用，但也就是使用命令showiproute時，所顯示在最上面的條目被優(yōu)先使用，正因?yàn)?72.16.0.0/16在192.168.1.0/24上面，所以被優(yōu)先使用。r3#shiprouteCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot *10.0.0.0/24issubnetted,1 r4#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic R*0.0.0.0/0[120/1]via20.1.1.3,00:00:14,r3(config-router)#noauto-summaryr4(config-router)#noauto-summaryr3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic 20.1.1.0isdirectlyconnected,FastEthernet0/110.0.0.0/24issubnetted,1subnets S*192.168.1.0/24[1/0]via10.1.1.1r4#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot 20.1.1.0isdirectlyconnected,FastEthernet0/1通過命令network，但network的網(wǎng)段必須為直連。r4#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic r3(config)#routereigrp1說明：R1通過RIP向R3通告192.168.1.0/24，R2通過EIGRP向R3r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic 20.1.1.0isdirectlyconnected,FastEthernet0/110.0.0.0/24issubnetted,1subnets R*192.168.1.0/24[120/1]via10.1.1.1,00:00:14, r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic 20.1.1.0isdirectlyconnected,FastEthernet0/110.0.0.0/24issubnetted,1subnets R*192.168.1.0/24[120/1]via10.1.1.1,00:00:23,D*192.168.2.0/24[90/156160]via10.1.1.2,00:01:17,r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic S*0.0.0.0/0[1/0]via20.1.1.4r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic 20.1.1.0isdirectlyconnected,FastEthernet0/1 172.16.0.0/16[1/0]via10.1.1.1 S*0.0.0.0/0[1/0]via20.1.1.4說明：ipdefault-network172.16.0.0是通過靜態(tài)路由指定的，有當(dāng)ipdefault-network后面的網(wǎng)段是通過靜態(tài)路由指定時，才優(yōu)先于iproute0.0.0.0R3ipdefault-networkRIPr3(config)#ipdefault-network192.168.1.0Codes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic 20.1.1.0isdirectlyconnected,FastEthernet0/1 172.16.0.0/16[1/0]via10.1.1.1 R*192.168.1.0/24[120/1]via10.1.1.1,00:00:13, S*0.0.0.0/0[1/0]via說明：ipdefault-network后面的網(wǎng)段是通過靜態(tài)路由指定時，才優(yōu)時iproute0.0.0.00.0.0.0優(yōu)先。IP網(wǎng)段劃分成多個子網(wǎng)，子網(wǎng)的掩碼可以是任意A8位才是主類網(wǎng)絡(luò)，B16位才是主類網(wǎng)絡(luò)，C類地址掩碼必須為24位才是主類網(wǎng)絡(luò)。ClasslessClassless可以與子網(wǎng)很好的協(xié)作，如果RIPEIGRP，并且這些功能ClasslessClassfulIOSClassless還是10.1.2.0/24Classless時，對于已經(jīng)知道的子網(wǎng)，路由器會將數(shù)據(jù)包精確地發(fā)送到相應(yīng)出口，而對于并不知道的子網(wǎng)和其它所有未知目標(biāo)網(wǎng)絡(luò)，如10.1.3.0/2430.1.1.0/24，如果存在默認(rèn)路由的話，路由器便將他們?nèi)堪l(fā)送到默認(rèn)路由所指示的出口；但是當(dāng)路由器工作在Classful時，路由器知道了子網(wǎng)的數(shù)據(jù)包會被發(fā)送到默認(rèn)路由指示的出口，而去往10.0.0.0/8中的未知子網(wǎng)10.1.3.0/24的數(shù)據(jù)包則被全部丟棄而不走默認(rèn)路由。ipclasslessnoipclassless開啟或關(guān)閉。r1(config-if)#ipadd12.1.1.1255.255.255.0r1(config-if)#noshr1(config-if)#ipadd10.1.1.1255.255.255.0r2(config-if)#ipadd12.1.1.2255.255.255.0r2(config-if)#noshr2(config-if)#noshr3(config-if)#noshr1(config-router)#network12.0.0.0r2(config-router)#network12.0.0.0r2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot Sending5,100-byteICMPEchosto10.1.1.1,timeoutis2Sending5,100-byteICMPEchosto10.1.3.1,timeoutis2Successrateis0percentSending5,100-byteICMPEchosto30.1.1.1,timeoutis2Successrateis0percent(0/5)Sending5,100-byteICMPEchosto10.1.3.1,timeoutis2Sending5,100-byteICMPEchosto30.1.1.1,timeoutis2所以通信成功。因?yàn)镮OS默認(rèn)工作在Classless。r2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstatic 23.1.1.0isdirectlyconnected,FastEthernet0/110.0.0.0/24issubnetted,1subnets S*0.0.0.0/0[1/0]via23.1.1.3Sending5,100-byteICMPEchosto10.1.3.1,timeoutis2Successrateis0percent(0/5)Sending5,100-byteICMPEchosto30.1.1.1,timeoutis2通信失敗，而到30.1.1.0/24通信正常。Sending5,100-byteICMPEchosto10.1.3.1,timeoutis2R210.1.3.0/24通信成功?！飅pdefault-networkiproute0.0.0.00.0.0.0配置了多條默認(rèn)網(wǎng)iproute0.0.0.00.0.0.0被優(yōu)先選用。AS內(nèi)傳遞路由信息。RP表，以供數(shù)據(jù)轉(zhuǎn)發(fā)。正因?yàn)槿绱?，對于路由是否正確，對于目標(biāo)是否可達(dá)，P全不可達(dá)，由此可見，RIP并不適合大型網(wǎng)絡(luò)。1使用廣播地址255.255.255.255ver2使用組播地址224.0.0.9發(fā)出。ver1ver230秒定期向網(wǎng)絡(luò)中發(fā)送，RIP沒有鄰RIPmetric1后發(fā)出去，雖然RIP采用定期更新，但是當(dāng)路由發(fā)生變化時，也會立即發(fā)送更新，如果檢測到某路RIPver1ver2，如果在配置RIPver1ver2的更新，但默認(rèn)只發(fā)送ver1，可以通過手工配置接口接收或發(fā)送更新版本的能力。ver2才可以啟用認(rèn)證，而ver1是不可以的，認(rèn)證同時支持明文和RIPver1會將收到的路由自動匯總為主類網(wǎng)絡(luò)，并且無法關(guān)閉該功能，為什么RIPver1RIPver1更新中，路由條目只ver1有一套奇怪的規(guī)則，在后面的實(shí)驗(yàn)中，將會詳細(xì)解釋。RIPver2RIPver1的某些缺點(diǎn)，就是在發(fā)送路由更新時，將路由的掩碼一起發(fā)送，于是成就了RIPver2ClasslessInterdomainRouting(CIDR)和Variable-LengthSubnetMasksVLSMs)RIPver2默認(rèn)也會自動匯總，只不過該功能可以手工關(guān)閉，同時，RIP還支持手工匯總路由信息，但手工匯總也是有RIPver1RIPver2，都可以在接口上關(guān)閉發(fā)送路由的功能，該功能接口收到路由更新，不會再從這個接口將收到的路由發(fā)回去。默認(rèn)情況下，F(xiàn)rame-FelayFrame-Felay點(diǎn)到點(diǎn)子接口還是多點(diǎn)子接口HDLC封裝的串口，以太網(wǎng)接口也都是默認(rèn)開啟RIPver1RIPver1255.255.255.255發(fā)送路由更新，所以同網(wǎng)段任何節(jié)點(diǎn)都RIPver1會將收到的路由自動匯總為主類網(wǎng)絡(luò)，并且無法關(guān)閉該功能，結(jié)果為RIPver18位，16位，24位其中的RIPver1IPIP地址相同的掩碼長度，比如248位掩碼。由此可以看出，RIP給路由的址的掩碼長度賦予接收路由，例如收到的路由為10.1.2.0，而接口主IP地址為位，所以RIP采用SecondaryIP的掩碼長度優(yōu)先。RIPIP地址和自己是同子網(wǎng)的，認(rèn)為雙方RIP路由器自己認(rèn)為而已，它并沒有辦法知道對方是否真的與自己在同一子網(wǎng)。有時，RIP希望避免造成不必要的錯誤，比如自己有條10.1.3.0/25，當(dāng)要將該路由從某個接口發(fā)出去之前，都會做一次檢測，10.1.1.0/24的IP地址，如果對方收到10.1.3.0，必定會將掩碼定義為24位（10.1.3.024測試RIPver1r1(config-if)#ipadd10.1.1.1255.255.255.0r1(config-if)#noshr2(config-if)#noshr3(config-if)#noshRIPver1r1#debugipRIPprotocoldebuggingison*Mar100:14:12.939:RIP:sendingv1updateto255.255.255.255*Mar100:14:12.939:RIP:buildupdate*Mar1 *Mar100:14:14.959:RIP:sendingv1updateto255.255.255.255*Mar100:14:14.959:RIP:buildupdate*Mar1 *Mar100:14:16.287:RIP:sendingv1updateto255.255.255.255*Mar100:14:16.287:RIP:buildupdateentries-suppressingnullupdate說明：RIP255.255.255.255ve1是不會加metric的，收到時是多少，放進(jìn)路由表還是多少。還可以看出RIPve1的r2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot 10.1.2.0的掩碼長度也是24主類，但是路由的掩碼長度與接口掩碼長度不同，所以R1就已經(jīng)放棄了發(fā)送r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot 很顯然，這是錯誤的，所以可以看出，當(dāng)RIPIP地址在同一主類，但掩r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot 10.1.0.0/23isdirectlyconnected,FastEthernet0/0r3#r2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot 10.1.1.0/24isdirectlyconnected,FastEthernet0/0r2#說明：R2給接口配置Secondary地址為10.1.1.22/25后，由于優(yōu)先采用了Secondary地址的掩碼長度賦予接收到的路由，所以原本的10.1.2.0/24變成了r1#debugipRIPprotocoldebuggingisonr1#conftEnterconfigurationcommands,oneperline.EndwithCNTL/Z.r1(config)#intloopback10*Mar100:24:41.895:RIP:sendingv1flashupdateto255.255.255.255*Mar100:24:41.895:RIP:buildflashupdate*Mar1 *Mar100:24:41.899:RIP:sendingv1flashupdateto255.255.255.255*Mar100:24:41.899:RIP:buildflashupdateentries-suppressing*Mar100:24:42.887:%LINEPROTO-5-UPDOWN:Lineprotocolon*Mar100:24:44.079:RIP:receivedv1updatefrom10.1.1.3*Mar1 10.1.2.0in16hops*Mar100:24:44.087:RIP:receivedv1updatefrom10.1.1.2*Mar100:24:44.087: 10.1.2.0in16hops(inaccessible)說明：RIP1516RIP認(rèn)為目標(biāo)不可達(dá)，RIPmetric值設(shè)R110.1.2.0shutdown后，R110.1.2.0metric16后發(fā)出RIPver1000000010000000032位的掩碼存放在路由表中。測試RIPver1說明：RIPver1主機(jī)路由，網(wǎng)絡(luò)基礎(chǔ)配置同r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot 說明：R32310.1.17.0與2310.1.17.0是否屬于0001000 00000009100000000010.1.17.0R3認(rèn)32位長度的掩碼放在路由表中，由此可見，RIP路由器雙方r2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot R10.1.31.0/32[120/1]via10.1.1.1,00:00:16,FastEthernet0/0R10.1.17.0/32[120/1]via10.1.1.1,00:00:17,FastEthernet0/0R10.1.41.0/32[120/1]via10.1.1.1,00:00:11,FastEthernet0/00，所以被當(dāng)作主機(jī)路由，要產(chǎn)生主機(jī)路由，可以手工配置對于接收者來說主機(jī)位并不是全為0的網(wǎng)段即要。r2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltypeE1-OSPFexternaltype1,E2-OSPFexternaltypei-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot RIPRIPIP地址或子網(wǎng)掩碼長度不匹配時，都會造成路由不精確或者路由表錯誤，因此，RIP收到的路由更新源地址必須和接收接口處于相同子網(wǎng)，即使是源地址和接收接口的Secondary地址處于相同子網(wǎng)也可以，否則忽略收到的路由更新，該功能稱為RIP的更新源有效性，可以手動去時，會同時使用主IP地址與Secondary地址分別發(fā)送一次。段不會被RIP更新出去。測試RIPr1(config-if)#ipadd10.1.1.1255.255.255.0r1(config-if)#noshr2(config-if)#ipadd10.1.1.2255.255.255.0r2(config-if)#noshr3(config-if)#ipadd30.1.1.3255.255.255.0r3(config-if)#noshr2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot 以下是R3上的debug信息：r3#debugipRIPprotocoldebuggingison*Mar100:08:32.219:RIP:sendingv1updateto255.255.255.255*Mar100:08:32.219:RIP:buildupdateentries-suppressingnull*Mar100:08:35.003:RIP:ignoredv1updatefrombadsource10.1.1.1r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot Secondary地址處于相同子網(wǎng)，最后將接收到的路由更新放r3(config)#routerrip說明：R3Secondary地址，再次查看路由r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot r3#debugipRIPprotocoldebuggingis*Mar100:17:20.971:RIP:ignoredv1updatefrombadsource10.1.1.1on*Mar100:17:20.971:RIP:receivedv1updatefrom30.1.1.1*Mar1 11.0.0.0in1r3#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot R2接收所有路由r2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-2ia-IS-ISinterarea,*-candidatedefault,U-per-usero-ODR,P-periodicdownloadedstaticGatewayoflastresortisnot 11.0.0.0/8[120/1]via30.1.1.1,00:00:06RIPRIPver1ver230秒定期向網(wǎng)絡(luò)中發(fā)送，用和節(jié)省廣域網(wǎng)上的帶寬，RIP可以調(diào)整為在廣域網(wǎng)鏈路上抑制路由更新的發(fā)送，而只僅僅在路由有變化時，將有變化的路由發(fā)出去，這就是RIPRIP是網(wǎng)絡(luò)早期開發(fā)的，在早期時候，廣域網(wǎng)都是串行鏈路，或者說是點(diǎn)RIPFrame-Relay點(diǎn)到點(diǎn)子接口被RIP認(rèn)為是點(diǎn)到點(diǎn)鏈路，可以開啟觸發(fā)更新。RIP路由器開啟觸發(fā)更新后，在路由沒有變動的情況下，便不再RIP觸發(fā)的更新機(jī)制需要在兩端路由器都開啟，否則不生效。在雙方都開啟后，注：RIPver1ver2測試RIP說明：以上圖為例，測試測試RIPr1(config-if)#encapsulationframe-relayr1(config-if)#noframe-relayinverse-arpr1(config-if)#noarpframe-relayr1(config-if)#noipaddress接，而Frame-Felay只有點(diǎn)到點(diǎn)子接口才被認(rèn)為是點(diǎn)到點(diǎn)鏈路。r2(config)#intserial1/0r2(config-if)#noframe-relayinverse-arpr2(config-if)#noarpframe-relayr2(config-if)#noipaddressr1#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2i-IS-IS,su-IS-ISsummary,L1-IS-ISlevel-1,L2-IS-ISlevel-ia-IS-ISinterarea,*-candidatedefault,U-per-userstaticrouteo-ODR,P-periodicdownloadedstaticrouteGatewayoflastresortisnot 10.1.1.0isdirectlyconnected,Loopback1012.0.0.0/24issubnetted,1subnets r2#shipCodes:C-connected,S-static,R-RIP,M-mobile,B-D-EIGRP,EX-EIGRPexter