第4層交換機(jī)的路由實(shí)現(xiàn)

1、第四章 多層交換機(jī)的路由實(shí)現(xiàn)神州數(shù)碼網(wǎng)絡(luò)前言多層交換設(shè)備能否進(jìn)行正常的網(wǎng)段間尋址的路徑轉(zhuǎn)發(fā)，關(guān)鍵在于是否正確的進(jìn)行了網(wǎng)段邊界的設(shè)定以及路由表是否正確生成，本章分析有關(guān)如何使多層交換設(shè)備實(shí)現(xiàn)多網(wǎng)段間的相互通信。學(xué)習(xí)目標(biāo)學(xué)完本課程之后，你應(yīng)該能：熟悉多層交換機(jī)功能概述掌握多層交換設(shè)備的直連網(wǎng)段掌握多層交換設(shè)備的靜態(tài)路由掌握多層交換設(shè)備的動(dòng)態(tài)路由多層交換機(jī)的功能概述多層交換機(jī)功能概述路由器的路由表Codes: C - connected, S - sic, R - RIP, B - BGP, BC - BGP connectedD - DEIGRP, DEX - external DEIGRP, O

2、 - OSPF, OIA - OSPFer areaON1 - OSPF NSSA external type 1, ON2 - OSPF NSSA external type 2OE1 - OSPF external type 1, OE2 - OSPF external type 2 DHCP - DHCP typeVRF ID: 0OCC10.10.10.1/3210.10.11.0/24192.168.1.0/24110,1601 via 192.168.1.1(on Serial1/0)is directly connected, Loack0is directly connecte

3、d, Serial1/0多層交換機(jī)功能概述三層交換機(jī)的路由表DCRS-7604#show ip routeTotal route items is 3, the matched route items is 3Codes: C - connected, S - sic, R - RIP derived, O - OSPF derivedA - OSPF ASE, B - BGP derived, D - DVMRP derivedDestinationMaskNexthoperfacePreferenceC CC192.168.10.0192.168.20.0192.168.100.0255.

4、255.255.0255.255.255.0255.255.255.00.0.0.00.0.0.00.0.0.0Vlan10 Vlan20Vlan100000DCRS-7604#多層交換機(jī)功能概述邏輯接口和物理接口邏輯接口VLAN 30VLAN 10VLAN 20物理接口10.1.1.110.2.2.110.3.3.1vlan 10vlan 20vlan 30232119171513119753124222018161412108642對(duì)應(yīng)的路由表DCRS-7604#show ip routeTotal route items is 4, the matched route items is

5、4Codes: C - connected, S - sic, R - RIP derived, O - OSPFderivedA - OSPF ASE, B - BGP derived, D - DVMRP derivedDestination PreferenceC 10.1.1.0C 10.2.2.0C 10.3.3.0 DCRS-7604#MaskNexthoperfaceVlan10 Vlan20 Vlan30255.255.255.0255.255.255.0255.255.255.00.0.0.00.0.0.00.0.0.0000單臂路由產(chǎn)生的瓶頸3-1VLAN之間的通信需要路由

6、器來完成VLAN增加導(dǎo)致數(shù)據(jù)量增大路由器與交換機(jī)之間路徑成為整個(gè)網(wǎng)絡(luò)的瓶頸VLAN 2VLAN 1單臂路由產(chǎn)生的瓶頸3-2增加路由器接口可以緩解流量瓶頸嗎？F0/0F0/1可以緩解瓶頸問題嗎？主機(jī)C主機(jī)BVLAN 20主機(jī)DVLAN 40主機(jī)AVLAN 10VLAN10單臂路由產(chǎn)生的瓶頸3-3單臂路由的缺陷“單臂”為網(wǎng)絡(luò)骨干鏈路，容易形成網(wǎng)絡(luò)瓶頸子接口依然依托于物理接口，應(yīng)用不靈活VLAN間轉(zhuǎn)發(fā)需要查看路由表，嚴(yán)重資源三層交換技術(shù)使用三層交換技術(shù)實(shí)現(xiàn)VLAN間通信三層交換=二層交換+三層轉(zhuǎn)發(fā)三層交換機(jī)采用硬件來交換和路擇數(shù)據(jù)包。如何實(shí)現(xiàn)？由選傳統(tǒng)的MLS2-13層轉(zhuǎn)發(fā)過程中要重新封裝2層三層交

7、換機(jī)上，第3層引擎處理數(shù)據(jù)流的第一個(gè)包數(shù)據(jù)ARP請(qǐng)求與響應(yīng)IP包頭數(shù)據(jù)VLAN 1VLAN 2CRC以太幀頭C以太I(xiàn)P包頭傳統(tǒng)的MLS2-2交換ASIC從3層引擎中獲悉2層重寫信息在硬件中創(chuàng)建一個(gè)MLS條目，負(fù)責(zé)重寫和轉(zhuǎn)發(fā)數(shù)據(jù)流中的后續(xù)數(shù)據(jù)包一次路由，多次交換IP包頭數(shù)據(jù)VLAN 2VLAN 1以太幀頭IP包頭數(shù)據(jù)CRC 包頭數(shù)據(jù)CRC以太幀頭基于CEF的MLSCEF是一種基于拓?fù)滢D(zhuǎn)發(fā)的模型轉(zhuǎn)發(fā)信息庫（FIB）鄰接關(guān)系表FIB表鄰接關(guān)系表交換機(jī)查找鄰接關(guān)系表主機(jī)B 10.20.20.2/24000c.295e.1743轉(zhuǎn)發(fā)主機(jī)A 10.10.10.2/24VLAN 1VLAN 20016.c7

8、2e.97000006.1be3.936600061BE393660016C72E9700000C295E17430016C72E970010.10.10.2/32VLAN 110.20.20.2/32VLAN 2虛接口概述2-1在三層交換機(jī)上配置的VLAN接口為虛接口虛接口的引入使得應(yīng)用更加靈活Switch(config)#erface vlan vlan-id虛接口概述2-2三層交換機(jī)VLAN間通信的轉(zhuǎn)發(fā)過程 vlan 20 vlan 10vlan 10vlan 20vlan 30端口屬于vlan 10端口屬于vTlarunn2k0主機(jī)問主機(jī)B主機(jī)A v主lan機(jī)1A0 vlan 10主機(jī)

9、B vla主n 機(jī)20Cvlan 30主機(jī)Bvlan 20主機(jī)B主機(jī)C小結(jié)請(qǐng)思考：CEF包含的兩個(gè)轉(zhuǎn)發(fā)信息表分別是什么？簡(jiǎn)述虛接口的作用，以及三層交換機(jī)VLAN間轉(zhuǎn)發(fā)過程？多層交換機(jī)的直連網(wǎng)絡(luò)三層交換機(jī)的配置在三層交換機(jī)啟用路由功能配置虛接口的IP配置路由接口Switch(config-if)# no switchportSwitch(config)#erface vlan vlan-id Switch(config-if)# ip address ip_addreetmask Switch(config-if)# no shutdownSwitch(config)# ip routing多層

10、交換機(jī)的靜態(tài)路由靜態(tài)路由設(shè)置分別分析三臺(tái)三層交換機(jī)將他們不直連的網(wǎng)段使用靜態(tài)路由指定上游需指定：2.2.2.0從1.1.1.1的下一跳走5.5.5.0從4.4.4.1的下一跳走左側(cè)和右側(cè)又該怎樣指定？多層交換機(jī)的動(dòng)態(tài)路由多層交換設(shè)備的動(dòng)態(tài)路由10.1.2.0.1.2.110.1.3.0.210.1.1.010.1.5.010.1.4.0Router ARouter BRouter CRouter Dt0t1t2t3NETVIAHOPS10.1.4.0 -010.1.5.0 -0 10.1.3.0 10.1.4.1 1 10.1.2.0 10.1.4.1 2 10.1.1.0 10.1.4.1

11、3NETVIAHOPS10.1.3.0 -010.1.4.0 -0 10.1.2.0 10.1.3.1 1 10.1.5.0 10.1.4.2 1 10.1.1.0 10.1.3.1 2NETVIAHOPS10.1.2.0 -010.1.3.0 -0 10.1.1.0 10.1.2.1 1 10.1.4.0 10.1.3.2 1 10.1.5.0 10.1.3.2 2NETVIAHOPS10.1.1.0 -010.1.2.0 -0 10.1.3.0 10.1.2.2 1 10.1.4.0 10.1.2.2 2 10.1.5.0 10.1.2.2 3NETVIAHOPS10.1.4.0 -010

12、.1.5.0 -0 10.1.3.0 10.1.4.1 1 10.1.2.0 10.1.4.1 2NETVIAHOPS10.1.3.0 -010.1.4.0 -0 10.1.2.0 10.1.3.1 1 10.1.5.0 10.1.4.2 1 10.1.1.0 10.1.3.1 2NETVIAHOPS10.1.2.0 -010.1.3.0 -0 10.1.1.0 10.1.2.1 1 10.1.4.0 10.1.3.2 1 10.1.5.0 10.1.3.2 2NETVIAHOPS10.1.1.0 -010.1.2.0 -0 10.1.3.0 10.1.2.2 1 10.1.4.0 10.1.

13、2.2 2NETVIAHOPS10.1.4.0-010.1.5.0-0NETVIAHOPS10.1.4.0-010.1.5.0-0 10.1.3.010.1.4.1 1NETVIAHOPS10.1.3.0-010.1.4.0-0NETVIAHOPS10.1.3.0 -010.1.4.0 -0 10.1.2.0 10.1.3.1 1 10.1.5.0 10.1.4.2 1NETVIAHOPS10.1.2.0-010.1.3.0-0NETVIAHOPS10.1.2.0 -010.1.3.0 -0 10.1.1.0 10.1.2.1 1 10.1.4.0 10.1.3.2 1NETVIAHOPS10

14、.1.1.0-010.1.2.0-0NETVIAHOPS10.1.1.0-010.1.2.0-0 10.1.3.010.1.2.2 1.2.1動(dòng)態(tài)路由在三層交換機(jī)中應(yīng)用全局下啟動(dòng)動(dòng)態(tài)路由協(xié)議的進(jìn)程開關(guān)在協(xié)議配置模式下配置網(wǎng)段vlan 中分別使用對(duì)應(yīng)命令使協(xié)議enablevlan 101.1.1.2vlan 404.4.4.2vlan 303.3.3.1vlan 404.4.4.1vlan 505.5.5.1Vlan50的用戶vlan 202.2.2.1vlan 101.1.1.1Vlan10的用戶Vlan30的用戶Vlan20的用戶Vlan40的用戶Vlan30的用戶IP: 3.3.3.121

15、-254/24 GW: 3.3.3.1IP: 4.4.4.0/24GW: 4.4.4.1IP: 5.5.5.0/24GW: 5.5.5.1IP: 2.2.2.0/24GW: 2.2.2.1IP: 3.3.3.2-120/24 GW: 3.3.3.1IP: 1.1.1.0/24GW: 1.1.1.1VLAN間路由相同接入層設(shè)備VLAN間213Vlan 10 Vlan 20 Vlan 30Vlan 30 Vlan 20Vlan 30Vlan 10vlan 10vlan 30vlan 20Vlan 30232224Vlan 10Vlan 20不同接入層設(shè)備VLAN內(nèi)Vlan 10Vlan 20Vla

16、n 30Vlan 30Vlan 20Vlan 30Vlan 10vlan 10vlan 30vlan 20Vlan 30232224Vlan 10Vlan 20不同接入層設(shè)備VLAN間213Vlan 10Vlan 20Vlan 30Vlan 30Vlan 20Vlan 30Vlan 10vlan 10vlan 30vlan 20Vlan 30232224Vlan 10Vlan 20多層交換設(shè)備的靜態(tài)路由trunktrunktrunktrunkVlan 30 Vlan 10Vlan 20 Vlan 30Vlan 10Vlan 30Vlan 30 Vlan 40Vlan 50Vlan 30Vlan

17、 40 Vlan 30邏輯拓?fù)涫疽鈜lan 11.1.1.2vlan 404.4.4.2vlan 303.3.3.1vlan 404.4.4.1nt vlan 505.5.5.1vlan 202.2.2.1nt vlan 101.1.1.1IP: 2.2.2.0/24GW: 2.2.2.1Vlan50的用戶IP: 5.5.5.0/24GW: 5.5.5.1IP: 1.1.1.0/24GW: 1.1.1.1Vlan10的用戶IP: 3.3.3.2-120/24GW: 3.3.3.1Vlan30的用戶Vlan20的用戶IP: 4.4.4.0/24GW: 4.4.4.1Vlan40的用戶IP: 3.

18、3.3.121-254/24GW: 3.3.3.1Vlan30的用戶內(nèi)網(wǎng)VLAN間的通信數(shù)據(jù)流vlan 30vlan 10vlan 40trunktrunkvlan 40vlan 50vlan 10vlan 20Vlan 30Vlan 10 Vlan 20Vlan 40 Vlan 50 Vlan 30三層交換機(jī)實(shí)現(xiàn)VLAN互通3-1需求描述按照?qǐng)D中規(guī)劃配置實(shí)現(xiàn)VLAN間互通Vlan 1：192.168.1.1/24 Vlan 2：192.168.2.1/24 Vlan 3：192.168.3.1/24SW-3Lf0/24192.168.1.156Vlan 1f0/24f0/1-10Vlan 2

19、 192.168.2.0/24192.168.1.0/24Vlan 3192.168.3.0/24f /11-15192.168.2.156f0/16-23192.168.3.156三層交換機(jī)實(shí)現(xiàn)VLAN互通3-2配置3層交換機(jī)在2層交換機(jī)上配置V啟動(dòng)路由T 功能k配置TrunkSW-3L(config)#ip routingSW-3L(config)#erface vlan 1SW-3L(config-if)#ip address 192.168.1.1 255.255.255.0 SW-3L(config-if)#no shut配置VLAN的IP地址SW-3L(config)#erface

20、 vlan 2SW-3L(config-if)#ip address 192.168.2.1 255.255.255.0SW-3L(config-if)#no shutSW-3L(config)#erface vlan 3SW-3L(config-if)#ip address 192.168.3.1 255.255.255.0SW-3L(config-if)#no shutSW-2L(config-if)#switchport mode trunk三層交換機(jī)實(shí)現(xiàn)VLAN互通3-3在三層交換機(jī)上查看路由表SW-3L#show ip routeCodes: C - connected, S - s

21、ic, R - RIP, M - mobile, B - BGPD - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPFer areaN1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGPi - IS-IS, su - IS-Immary, L1 - IS-IS level-1, L2 - IS-IS level-2ia - IS-ISer area, *

22、- candidate default, U - per-user sic routeo - ODR, P - periodic downloaded sic routeGateway of last resort is not setC 192.168.1.0/24 is directly connected, Vlan1 C 192.168.2.0/24 is directly connected, Vlan2 C 192.168.3.0/24 is directly connected, Vlan3在三層交換機(jī)上配置路由2-1需求描述配置路由實(shí)現(xiàn)內(nèi)網(wǎng)路由器及其f0/23 10.1.1.1

23、/30Vlan 1：192.168.1.1/24 Vlan 2：192.168.2.1/24 Vlan 3：192.168.3.1/24Routerf0/0 10.1.1.2/30SW-3Lf0/24192.168.1.156Vlan 1f0/24f0/1-10Vlan 2 192.168.2.0/24192.168.1.0/24Vlan 3 192.168.3.0/24f /11-15192.168.2.156f0/16-22192.168.3.156在三層交換機(jī)上配置路由2-2V在L三AN層、交Tr換un機(jī)k配上置查看路由表SW-3L#show ip route Codes: C - co

24、nnected, S - sic, R - RIP, M - mobile, B - BGP址D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPFer areaN1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGPi - IS-IS, su - IS-Immary, L1 - IS-IS level-1, L2 - IS-IS level-2ia - IS-ISer area, * - candidate default, U - per-user sic routeGateway o