路由器交换机基础知识基本配置

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1、 路由器和交换机路由器和交换机 基础知识与基本配置基础知识与基本配置路由器与交换机的作用与特点路由器与交换机的作用与特点交换机基础与基本配置交换机基础与基本配置路由器基础与基本配置路由器基础与基本配置目录目录交换机的作用PCB PCA PCDPCCSWA SWB 连接多个以太网物理段，隔离冲突域对以太网帧进行高速而透明的交换转发自行学习和维护MAC地址信息交换机的特点主要工作在OSI模型的物理层、数据链路层提供以太网间的透明桥接和交换依据链路层的MAC地址，将以太网数据帧在端口间进行转发 路由器的作用RTC RTBRTA RTD RTE PCB PCA 连接具有不同介质的链路连接网络或子网，隔

2、离广播对数据报文执行寻路和转发交换和维护路由信息路由器的特点主要工作在OSI模型的物理层、数据链路层和网络层根据网络层信息进行路由转发提供丰富的接口类型支持丰富的链路层协议支持多种路由协议路由器与交换机的发展趋势路由和交换的融合多业务功能的融合路由器与交换机的作用与特点路由器与交换机的作用与特点交换机基础与基本配置交换机基础与基本配置路由器基础与基本配置路由器基础与基本配置本章目录本章目录目标目标交换原理VLAN原理生成树协议其本原理交换机基本配置交换机特性介绍地址学习转发/过滤防止环路交换机的三大功能 交换机的地址学习功能起初MAC地址表是空的MAC address table0260.8c

3、01.11110260.8c01.22220260.8c01.33330260.8c01.4444E0E1E2E3ABCD交换机的地址学习功能工作站 A 向工作站 C 发送一个数据帧交换机分析该帧，帧的头部记录了源地址A，交换机由此知道工作站是连接在端口E0之上的 由于MAC地址表中没有C工作站的记录，所以交换机向所有的端口转发该帧（Flood 泛洪）MAC address table0260.8c01.11110260.8c01.22220260.8c01.33330260.8c01.4444E0: 0260.8c01.1111E0E1E2E3DCBA交换机的地址学习功能同样，工作站B给A发

4、数据包的时候，交换机将其MAC地址和端口关联起来MAC地址表记录了这样的一种关联，用于专用的集成电路ASIC的转发依据转发数据由ASIC完成，不再需要CPU参与MAC address table0260.8c01.11110260.8c01.22220260.8c01.33330260.8c01.4444E0: 0260.8c01.1111E1: 0260.8c01.3333E0E1E2E3DCAB交换机的过滤功能MAC地址表建立之后，当工作站A往工作C发送数据包，交换机知道只需要转发到端口E2, 不需要复制到E1、E3, 这就是交换机的过滤功能过滤功能减少了网络流量对工作站的干扰，提高了可用

5、带宽 E0: 0260.8c01.1111E2: 0260.8c01.2222E1: 0260.8c01.3333E3: 0260.8c01.44440260.8c01.11110260.8c01.22220260.8c01.33330260.8c01.4444E0E1E2E3X XX XDCABMAC address table网络拓扑冗余冗余的网络拓朴结构可以防止单点故障，但也带来一些问题: 广播风暴、重复帧、MAC地址表不稳定Segment 1Segment 2Server/host XRouter YSegment 1Segment 2Server/host XRouter Y Bro

6、adcastSwitch ASwitch B主机 X 发送的广播包由交换机A发送到网段2广播风暴Segment 1Segment 2Server/host XRouter Y BroadcastSwitch ASwitch B交换机B把广播包又转发到网段1广播风暴Segment 1Segment 2Server/host XRouter Y Broadcast广播包就这样被反复传送直到占完带宽，造成网络服务中断Switch ASwitch B广播风暴端口速度Cost (当前 IEEE 规范) Cost (前 IEEE 规范)-10 Gbps 211 Gbps41100 Mbps191010 M

7、bps100100生成树协议的路径成本生成树协议 通过引入生成树协议，交换机把某些端口置于阻断状态，避免环路问题BlockxIEEE 802.3d在一个网络中只存在一个根桥(root bridge)非根桥上只有一个根端口(到根桥的cost最低)在每一个网段上只有一个指定端口(designated port)xDesignated port (F)Root port (F)Designated port (F)Nondesignated port (B)Root bridgeNonroot bridgeSW XSW Y100baseT 10baseT生成树基本原理Switch YDefault

8、priority 32768MAC 0c0022222222Switch XDefault priority 32768 MAC 0c0011111111Root bridgexPort 0Port 1Port 0Port 1100baseT10baseT Designated port (F)Root port (F)Nondesignated port (B)Designated port (F)生成树协议的端口状态F Forward 转发状态 B Blocking阻断状态非指定端口将被交换机置于阻断状态，其它端口（根端口、指定端口）都将工作于转发状态Blocking 阻断 (20 sec

9、)Listening 侦听 (15 sec) Learning 学习 (15 sec)Forwarding 转发在进行数据转发之前端口依次要经过以下几种状态以默认参数工作时整个过程需要50秒！生成树协议端口状态Switch YMAC 0c0022222222Default priority 32768Switch XMAC 0c0011111111Default priority 32768 Port 0Port 1Port 0Port 110baseTx x100baseTRoot BridgeDesignated portRoot port (F)Nondesignated port (B

10、LK)Designated port生成树重计算如果网络拓朴发生变化，生成树必须要进行重新计算，以启用必要的链路Switch YMAC 0c0022222222Default priority 32768Switch XMAC 0c0011111111Default priority 32768 Port 0Port 1Port 0Port 110baseTx x100baseTRoot BridgeDesignated portRoot port (F)Nondesignated port (BLK)Designated portBPDUx xMAXAGEx x生成树重计算 交换机Y经过Ma

11、xage定义的时间仍收不到BPDU，可以认为根桥已经当掉，拓朴发生变化, 重新进行计算关键问题：会聚所需时间所有交换机完成计算，将端口置于阻断/转发状态之后整个网络就会聚完毕当网络的拓扑结构发生变化时，交换机必须重新计算生成树协议，这期间用户的数据传送被中断生成树协议的扩展与发展PVST :每个VLAN一个生成树PortFast: 端口快速进入转发状态RSTP/MSTP: 新一代的生成树PVST VLAN 10 用户群VLAN 20 用户群VLAN 10、20 少数用户x阻断状态Root BridgeVLAN10的流量并非最优路径选择合适的根桥可以优化流量PVST VLAN 10 用户群VLA

12、N 20 用户群VLAN 10、20 少数用户xRoot BridgeVLAN10的流量并非最优路径Root Bridgex调整生成树设置可以达到某种程度的负载均衡PortFast直接将端口置于转发状态，“立即可用”避免了生成树启动的一些问题：如DHCP失败只应在连接主机的端口上使用3550高级特性：避免交换机间的端口工作于PortFast方式快速生成树非常快的收敛速度，使生成树计算对网络数据的影响降到最小分区域（等级）的生成树增强了扩展性标准化技术，向后兼容目前仅3550, 6500等部分高档交换机支持，推荐应用于中心接入Half duplex (CSMA/CD)单向数据冲突率高一般出现在用

13、HUB的情况 SwitchHub半双工SwitchHubFull duplex 点对点每个交换机端口上只连接一台设备双方都支持(可通过自动协议选定)不会有冲突发生 冲突检测自动关闭全双工Half duplex (CSMA/CD)单向数据冲突率高一般出现在用HUB的情况 划分网段灵活性安全性三楼二楼一楼用电财务工区VLAN 把一组物理设备划分为多个逻辑网络 VLAN 概述Switch AGreenVLANBlackVLAN RedVLANVLAN之间互相隔离，就好象用户连接到不同的交换机一样VLAN的特点Switch AGreenVLANBlackVLAN RedVLANSwitch BGree

14、nVLANBlackVLANRedVLANVLAN之间互相隔离，就好象用户连接到不同的交换机一样VLAN可以跨越多个交换机VLAN的特点Switch AGreenVLANBlackVLAN RedVLANSwitch BGreenVLANBlackVLANRedVLAN TrunkVLAN之间互相隔离，就好象用户连接到不同的交换机一样VLAN可以跨越多个交换机TRUNK(干道)传送多个VLAN的数据，它们使用“封装”标记不同VLAN的数据 Fast EthernetVLAN的特点38VLANVLAN指定：动态与静态指定：动态与静态VLAN5Static VLANDynamic VLANMAC

15、= 1111.1111.1111TrunkVMPS1111.1111.1111 = vlan 10 VLAN10Port e0/9Port e0/439封装：标记封装：标记ISL是cisco专有技术802.1Q是开放标准可用于交换机之间或交换机与主机、路由器之间由于新技术的发展，已经逐步统一于dot1qISL 或802.1Q封装方法通过TRUNK传输前加上标记去掉标记传输VTPVTPVLAN Trunk Protocol 照字面翻译是VLAN 干道协议，但其实称为VLAN管理协议更合适VTP在一个由多台交换机组成的域内创建、修改和同步VLAN数据库VTP 信息只通过TRUNK传输支持混合介质(

16、以太网，ATM) 1.“已建立新的VLAN”3.获知新VLAN的信息2VTP Domain “JSEPC”41VTP VTP 角色角色ServerClientTransparent转发通告信息同步VLAN信息不在NVRAM中保存VLAN信息建立VLAN修改VLAN删除VLAN发送/转发通告同步VLAN信息在NVRAM保存信息创建VLAN修改VLAN删除VLAN转发通告不同步到域在 NVRAM中保存42VTP VTP 操作操作VTP 使用组播方式发送通告 VTP server 和 client 同步到最新版本的VLAN数据库VTP 通告每五分钟发送一次，或当VLAN数据库有修改时发送VTP 使用

17、组播方式发送通告 VTP server 和 client 同步到最新版本的VLAN数据库VTP 通告每五分钟发送一次，或当VLAN数据库有修改时发送1.创建新 VLAN2.修改VLAN数据库版本号: Rev 3 - Rev 4 ServerClientClient4.Rev 3 - Rev 45.同步到新的VLAN数据库 334.Rev 3 - Rev 45.同步到新的VLAN数据库 同步过程热点问题：安全手段只允许特定机器使用该端口: port secureWAN只允许特定机器(mac)使用某IP: 静态ARP指定只允许特定IP访问某些资源:访问控制列表ACL配置安全手段Port Secur

18、e: (二层交换机)inter f 0/12port security max-mac-count 1port security action shutdown!mac-address-table secure 000C.00AB.1129 f 0/12静态ARP指定: (路由)arp 192.168.1.1 0001.0001.0001 arpa访问控制列表: (路由)Access-list 100 deny icmp any anyAccess-list 100 permit ip any anyInter vlan 1 ip access-group 100 out思科交换机基本配置配置

19、方式：console、telnet: CLI命令行方式web方式snmp方式系统启动程序初始交换机的软件。初始启动使用默认的配置参数。Catalyst交换机的初始启动 Catalyst 3560交换机的LED 指示灯在自检期间端口LEDs 状态 1. 启动时, 所有端口LEDs都是绿色恒亮。2. 交换机完成所有端口测试之后每个端口LED均熄灭。3. 如果某端口测试失败, 所对应LED 变成琥珀（黄）颜色。4. 只要有测试失败，系统LED变成琥珀（黄）颜色。5. 若无测试失败，自检（POST）完成。6.象征POST完成： LEDs 闪烁,然后熄灭。交换机常用配置方式配置方式：console、te

20、lnet: CLI命令行方式web方式snmp方式连接交换机第一次连接交换机，配置终端参数为: 波特率：9600；数据位：8；停止位：1；奇偶校验：无；流控制：无。连接上后看到：Switch用户命令行模式命令模式3560 交换机SwitchSwitch#Switch(config)#Switch(config-if)#Switch(config-line)#配置主机名3560交换机Switch#Conf tSwitch(config)#hostname 3500_A3500_A(config)#exit3500_A#write保存配置配置密码3560交换机:Switch(config)#ena

21、ble secret _passwordSwitch(config)#line vty 0 15Switch(config-line)#password _password3560的端口命名方式快速以太网端口：fastethernet 0/0 0/48千兆以太网端口：gigaethernet 0/1 管理端口： vlan 1 (或vlan n)设置端口速度/双工3560交换机:Switch(config)# interface f 0/1Switch(config-if)#speed 100Switch(config-if)#duplex full检查端口状态3560交换机:Switch# s

22、how interface f 0/1如果端口速度/双工不匹配可能的现象：完全不通错误数多（端口可能会自动关闭，数据传输可能会意外中断）端口flap (up-down-up-down)设置管理IP地址3560交换机:Switch(config)#inter vlan 1Switch(config-if)#ip add 1.1.1.1 255.255.255.0设置网关3560交换机:Switch(config)#ip route 0.0.0.0 0.0.0.0 1.1.1.254设置TRUNK3560交换机:Switch(config)#inter g 0/1Switch(config-if)

23、#switch trunk enc dot1qSwitch(config-if)#switch mode trunk检查TRUNK3560交换机:Switch#show inter g 0/1 switchport设置VTP3560交换机:Switch#vlan databaseSwitch(config-if)#switch trunk enc dot1qSwitch(vlan)# vtp client(或server)Switch(vlan)# vtp domain _domainSwitch(vlan)# exit检查VTP3560交换机:Switch#show vtp status如果

24、没有同步检查端口:show interfaceshow port检查trunk:show trunkshow inter f0/1 switch检查VTP参数：版本、域名、模式、密码show vtp statusshow vtp domain检查其它配置：show run添加VLAN3560交换机: (VTP模式为Server/Tran时)Switch#vlan databaseSwitch(vlan)#vlan 2 name ydcSwitch(vlan)#vlan 3 name ccd检查VLAN3560交换机: (VTP模式为Server/Tran时)Switch#show vlan把端

25、口指定的VLAN3560交换机:Switch(config)#interface f0/1Switch(config-if)#switch access vlan 2检查端口所在VLAN3560交换机:Switch#show vlan 路由器与交换机的作用与特点路由器与交换机的作用与特点交换机基础与基本配置交换机基础与基本配置路由器基础与基本配置路由器基础与基本配置本章目录本章目录n路由器负责将数据报文在逻辑网段间进行转发路由器负责将数据报文在逻辑网段间进行转发n路由是指导路由器如何进行数据报文发送的路径信息路由是指导路由器如何进行数据报文发送的路径信息n每台路由器都有路由表，路由存储在路由表

26、中每台路由器都有路由表，路由存储在路由表中n路由环路是由错误的路由导致的，它会造成路由环路是由错误的路由导致的，它会造成IP报文在报文在网络中循环转发，浪费网络带宽网络中循环转发，浪费网络带宽引入引入什么是路由l路由是指导路由是指导IP报文发送的路径信息报文发送的路径信息RTBRTCRTDRTERTA网络N（N,RTB）（N,RTC）（N,RTD）（N,RTE）PCServer路由表的构成l路由表是路由器转发报文的判断依据。路由表是路由器转发报文的判断依据。E0/010.0.0.2/2420.0.0.0/24目的地址目的地址/掩码掩码下一跳地址下一跳地址出接口出接口度量值度量值0.0.0.0/

27、020.0.0.2E0/21010.0.0.0/2410.0.0.1E0/1020.0.0.0/2420.0.0.1E0/2020.0.0.1/32127.0.0.1InLoop0040.0.0.0/2420.0.0.2E0/2140.0.0.0/830.0.0.2E0/3350.0.0.0/2440.0.0.2E0/20路由器单跳操作查找路由表IP报文入站查看下一跳地址送往接口转发丢弃没有匹配路由在直连链路上以下一跳作为目的地址不在直连链路上报文封装有匹配路由路由表查找规则（1）目的地址目的地址/掩码掩码下一跳地址下一跳地址出接口出接口度量值度量值10.0.0.0/2410.0.0.1E0/

28、1020.0.0.0/2420.0.0.1E0/2020.0.0.1/32127.0.0.1InLoop0040.0.0.0/2420.0.0.2E0/2140.0.0.0/830.0.0.2E0/3350.0.0.0/2440.0.0.2E0/20E0/220.0.0.2/2440.0.0.0/24E0/1E0/310.0.0.2/24最长匹配然后转发目的地址40.0.0.2的报文入站路由表查找规则（2）目的地址目的地址/掩码掩码下一跳地址下一跳地址出接口出接口度量值度量值10.0.0.0/2410.0.0.1E0/1020.0.0.0/2420.0.0.1E0/2020.0.0.1/321

29、27.0.0.1InLoop0040.0.0.0/2420.0.0.2E0/2140.0.0.0/830.0.0.2E0/3350.0.0.0/2440.0.0.2E0/20E0/220.0.0.2/2440.0.0.0/24E0/1E0/310.0.0.2/24转发目的地址50.0.0.2的报文入站路由表查找规则（3）目的地址目的地址/掩码掩码下一跳地址下一跳地址出接口出接口度量值度量值0.0.0.0/020.0.0.2E0/21010.0.0.0/2410.0.0.1E0/1020.0.0.0/2420.0.0.1E0/2020.0.0.1/32127.0.0.1InLoop0040.0.

30、0.0/2420.0.0.2E0/2140.0.0.0/830.0.0.2E0/3350.0.0.0/2440.0.0.2E0/20E0/220.0.0.2/2440.0.0.0/24E0/1E0/310.0.0.2/24转发目的地址30.0.0.2的报文入站路由的来源l直连路由直连路由开销小，配置简单，无需人工维护。只能发现本接口所属网段的路由。l手工配置的静态路由手工配置的静态路由无开销，配置简单，需人工维护，适合简单拓扑结构的网络。l路由协议发现的路由路由协议发现的路由开销大，配置复杂，无需人工维护，适合复杂拓扑结构的网络。路由度量值（Metric）l路由度量值表示到达这条路由所指目的地

31、址路由度量值表示到达这条路由所指目的地址的代价。的代价。l通常影响路由度量值的因素：通常影响路由度量值的因素：线路延迟、带宽、线路使用率、线路可信度、跳数、最大传输单元l不同路由协议参考的因素不同不同路由协议参考的因素不同路由类型路由类型度量值参考因素度量值参考因素静态路由（静态路由（Static）固定值，固定值，0OSPF路由协议路由协议带宽带宽RIP路由协议路由协议跳数跳数如果到相同目的地址有多个路由来源，则：以Preference（优先级）确定不同类型优先级Preference越小，优先级越高优先级最高的路由被添加进路由表目的网段比较生效路由优先级比较添加到路由表不同相同优先级高路由优先

32、级路由环路Routing Table目标网络目标网络接口接口权值权值11.4.0.0.S0/04Routing Table目标网络目标网络接口接口权值权值11.4.0.0S0/12Routing Table目标网络目标网络接口接口权值权值11.4.0.0S1/03E1/0S0/0S0/0S1/0S0/011.1.0.011.4.0.0RTARTBRTCS0/1E1/0S0/1l环路产生的原因：配置错误或协议缺陷环路产生的原因：配置错误或协议缺陷思科路由器基本配置命令配置密码Router(config)# line console 0Router(config-line)# loginRoute

33、r(config-line)# password ciscoConsole Password Virtual Terminal Password Router(config)# line vty 0 4Router(config-line)# login Router(config-line)# password ciscoEnable Password Router(config)# enable secret san-franPerform Password EncryptionRouter(config)# service password-encryption(set password

34、s here)Router(config)# no service password-encryption配置路由器的标示Router NameRouter(config)# hostname TokyoTokyo#Login BannerTokyo(config)# banner motd #Welcome to router TokyoAccounting Department3rd Floor#Interface DescriptionTokyo(config)# interface e 0Tokyo(config-if)# description Engineering LAN, Bl

35、dg. 18为路由器及其端口配置标示信息Router (config-if) #分配地址和掩码针对端口配置IP地址设定允许使用子网掩码配置 IP 地址ip address ip-address subnet-maskRouter (config) #ip subnet-zeroDefines a path to an IP destinationnetwork or subnetip route network mask address | interface distance Router (config) #配置静态路由举例:静态路由ip route 172.16.1.0 255.255.

36、255.0 172.16.2.1172.16.2.0Cisco A172.16.1.0 255.255.255.0172.16.2.1Cisco BE0S0S1S2S0172.16.2.2Router# show running-configBuilding configuration.Current configuration:!version 11.2!- More -Router# show startup-configUsing 1108 out of 130048 bytes!version 11.2!hostname router- More -show running-confi

37、g 命令 show startup-config 命令Use write terminal with Release 10.3 and earlierUse show config with Release 10.3 and earlierRouterA#show versionCisco Internetwork Operating System SoftwareIOS (tm) 2500 Software (C2500-JS40-L), Version 11.2(5), RELEASE SOFTWARE (fc1)Copyright (c) 1986-1997 by cisco Syste

38、ms, Inc.Compiled Tue 01-Apr-97 09:12 by ckralikImage text-base: 0x0303F9A8, data-base: 0x00001000ROM: System Bootstrap, Version 5.2(8a), RELEASE SOFTWAREROM: 3000 Bootstrap Software (IGS-RXBOOT), Version 10.2(8a), RELEASE SOFTWARE (fc1)RouterA uptime is 1 day, 5 hours, 50 minutesSystem restarted by

39、reloadSystem image file is flash:c2500-js40-l.112-5.bin, booted via flash-More-show version 命令cisco 2522 (68030) processor (revision M) with 14336K/2048K bytes of memory.Processor board ID 05614645, with hardware revision 00000002Bridging software.SuperLAT software copyright 1990 by Meridian Technol

40、ogy Corp).X.25 software, Version 2.0, NET2, BFE and GOSIP compliant.TN3270 Emulation software (copyright 1994 by TGV Inc).Basic Rate ISDN software, Version 1.0.1 Ethernet/IEEE 802.3 interface(s)2 Serial network interface(s)8 Low-speed serial(sync/async) network interface(s)1 ISDN Basic Rate interfac

41、e(s)32K bytes of non-volatile configuration memory.16384K bytes of processor board System flash (Read ONLY)Configuration register is 0x2102RouterA#show versionRouterA# show protocolsGlobal values: Internet Protocol routing is enabled DECNET routing is enabled XNS routing is enabled Appletalk routing

42、 is enabled Novell routing is enabled -More- Ethernet0 is up, line protocol is up Internet address is 183.8.128.2, subnet mask is 255.255.255.128 Decnet cost is 5 XNS address is 3010.aa00.0400.0284 AppleTalk address is 3012.93, zone ld-e0 Novell address is 3010.aa00.0400.0284 -More-show protocols 命令

43、Router show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate defaultGateway of

44、 last resort is not set 144.253.0.0 is subnetted (mask is 255.255.255.0), 1 subnetsC 144.253.100.0 is directly connected, Ethernet1R 133.3.0.0 R 153.50.0.0 120/1 via 183.8.128.12, 00:00:09, Ethernet0 183.8.0.0 is subnetted (mask is 255.255.255.128), 4 subnetsR 183.8.0.128 120/1 via 183.8.128.130, 00

45、:00:17, Serial0 120/1 via 183.8.64.130, 00:00:17, Serial1C 183.8.128.0 is directly connected, Ethernet0C 183.8.64.128 is directly connected, Serial1C 183.8.128.128 is directly connected, Serial0R 192.3.63.0 列出 IP 路由表Router show ip protocolRouting Protocol is igrp 300 Sending updates every 90 seconds

46、, next due in 55 seconds Invalid after 270 seconds, hold down 280, flushed after 630 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 IGRP m

47、etric weight K1=1, K2=0, K3=1, K4=0, K5=0 IGRP maximum hopcount 100 IGRP maximum metric variance 1 Redistributing: igrp 300 Routing for Networks: 183.8.0.0 144.253.0.0 Routing Information Sources: Gateway Distance Last Update 144.253.100.1 100 0:00:52 183.8.128.12 100 0:00:43 183.8.64.130 100 0:01:0

48、2 Distance: (default is 100) -More-show ip protocol 命令Router show ip interfacesEthernet0 is up, line protocol is up Internet address is 183.8.128.2, subnet mask is 255.255.255.128 Broadcast address is 255.255.255.255 Address determined by non-volatile memory MTU is 1500 bytes Helper address is not s

49、et Directed broadcast forwarding is enabled Outgoing access list is not set Inbound access list is not set Proxy ARP is enabled Security level is default Split horizon is enabled ICMP redirects are always sent ICMP unreachables are always sent ICMP mask replies are never sent IP fast switching is en

50、abled IP fast switching on the same interface is disabled IP SSE switching is disabled Router Discovery is disabled IP output packet accounting is disabled IP access violation accounting is disabled TCP/IP header compression is disabled Probe proxy name replies are disabled -More-show ip interfaces

51、命令Router show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate defaultGateway

52、of last resort is not set 144.253.0.0 is subnetted (mask is 255.255.255.0), 1 subnetsC 144.253.100.0 is directly connected, Ethernet1I 133.3.0.0 100/1200 via 144.253.100.200, 00:00:57, Ethernet1I 153.50.0.0 100/1200 via 183.8.128.12, 00:00:05, Ethernet0 183.8.0.0 is subnetted (mask is 255.255.255.12

53、8), 4 subnetsI 183.8.0.128 100/180671 via 183.8.64.130, 00:00:27, Serial1 100/180671 via 183.8.128.130, 00:00:27, Serial0C 183.8.128.0 is directly connected, Ethernet0C 183.8.64.128 is directly connected, Serial1C 183.8.128.128 is directly connected, Serial0I 172.16.0.0 100/1200 via 144.253.100.1, 0

54、0:00:55, Ethernet1I 192.3.63.0 100/1300 via 144.253.100.200, 00:00:58, Ethernet1show ip route 命令RAMInternetwork Operating SystemProgramsTables and BuffersActiveConfigurationFileBackupConfigurationFileOperating SystemsInterfacesRouter 状态检查命令Router# show versionFlashRouter# show processes CPURouter# s

55、how protocolsRouter# show memRouter# show stacksRouter# show buffersRouter# show flashRouter# show running-configRouter# write termRouter# show startup-configRouter# show configNVRAMRouter# show interfaces密码在Cisco设备上配置控制端口密码xxzx3640(config)#line console 0xxzx3640(config-line)#loginxxzx3640(config-li

56、ne)#password ciscoxxzx3640(config-line)#login local/tacacsxxzx3640(config-line)#username xxx password xxxxxzx3640(config-line)#access-class 1 in控制会话超时RSM143(config)#line console 0RSM143(config-line)#exec-timeout 5 30RSM143(config)#line vty 0 4RSM143(config-line)#exec-timeout 5 3DSW141 (enable) set l

57、ogout 5 ASW41(config)#line consoleASW41(config-line)#time-out 300 IOS交换机Set 命令交换机IOS 路由器privilege configure level 3 usernameprivilege exec level 3 copy run startprivilege exec level 3 pingprivilege exec level 3 show runprivilege exec level 3 showenable secret level 3 cisco特权级别通过修改用户的特权级别，你可以为用户分配更细微

58、的权限IOS路由器 特权级访问xxzx3640(config)#enable secret level 3 ciscouser xxzx3640(config)#privilege exec level 3 xxxRuns on routers with Cisco IOS 10.3 or later and Cisco switches and hubsSummary information includes:Device identifiersAddress listPort identifierCapabilities listPlatform CDPshow cdpCDPCDP使用CD

59、P查看邻居S0S0E0Router AE0Frame Relay WANRouter BCDP 配置举例RouterA#show cdp interfaceSerial0 is up, line protocol is up, encapsulation is Frame Relay Sending CDP packets every 60 seconds Holdtime is 180 secondsEthernet0 is up, line protocol is up, encapsulation is ARPA Sending CDP packets every 60 seconds

60、Holdtime is 180 secondsrouterA (config-if)# cdp enableEnable CDP on each interface使用CDP命令SwitchBRouterARouterBSwitchA10.3.3.210.3.3.110.1.1.110.1.1.210.2.2.110.2.2.2S0S1RouterA#sh cdp ? entry Information for specific neighbor entry interface CDP interface status and configuration neighbors CDP neigh

61、bor entries traffic CDP statistics RouterA(config)#no cdp run RouterA(config)#interface serial0 RouterA(config-if)#no cdp enable Showing CDP NeighborsRouterA#show cdp neighborsCapability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge, S - Switch, H - Host, I - IGMPDevice ID Local Intrf

62、ce Holdtme Capability Platform Port ID Router Ser 0 151 R 2522 Ser 1 SwitchA0050BD855780 Eth 0 165 T s 1900 2RouterA#show cdp neighbors detail-Device ID: RouterBEntry address(es): IP address: 198.121.200.1 Novell address: 1002.0000.0c01.1111Platform: cisco 2522, Capabilities: RouterInterface: Serial

63、1, Port ID (outgoing port): Serial0Holdtime : 149 sectelnet 操作Initiate a sessionDenver telnet parisEnd a sessionParis exitSuspend a sessionEscape sequenceParis DenverResume a sessionDenver Disconnect a sessionDenver disconnect parisDisplay sessionsDenver# show sessionsConnHostAddressIdleConn Name 1P

64、aris131.108.100.152 0Paris 2Tokyo127.102.57.63 0Tokyo*TokyoParisDenver使用Telnet连接远程设备Remote deviceSwitchBRouterARouterBSwitchA10.3.3.210.3.3.110.1.1.110.1.1.210.2.2.110.2.2.2S0S1RouterA#telnet 10.2.2.2 Trying 10.2.2.2 . Open-Catalyst 1900 Management ConsoleCopyright (c) Cisco Systems, Inc. 1993-1998A

65、ll rights reserved.Enterprise Edition SoftwareEthernet Address: 00-90-86-73-33-40PCA Number: 73-2239-06PCA Serial Number: FAA02359H8KModel Number: WS-C1924-ENSystem Serial Number: FAA0237X0FQ.SwitchB查看Telnet连接SwitchBRouterARouterBSwitchA10.3.3.210.3.3.110.1.1.110.1.1.210.2.2.110.2.2.2S0S1RouterA#sh

66、sessionConn Host Address Byte Idle Conn Name 1 10.1.1.2 10.1.1.2 0 1 10.1.1.2* 2 10.3.3.2 10.3.3.2 0 0 10.3.3.2RouterA#sh user Line User Host(s) Idle Location* 0 con 0 10.1.1.2 3 10.3.3.2 2 11 vty 0 idle 1 10.1.1.2切换Telnet会话SwitchBRouterARouterBSwitchA10.3.3.210.3.3.110.1.1.110.1.1.210.2.2.110.2.2.2

67、S0S1RouterB#xRouterA#sh sessionConn Host Address Byte Idle Conn Name 1 10.1.1.2 10.1.1.2 0 1 10.1.1.2RouterA#resume 1RouterB#RouterA#disconnect Closing connection to 10.3.3.2 confirmRouterA#clear line 11confirm OK关闭Telnet会话Closing a session opened by a remote deviceClosing the current session opened

68、 by youSwitchBRouterARouterBSwitchA10.3.3.210.3.3.110.1.1.110.1.1.210.2.2.110.2.2.2S0S1使用 ping 命令测试各种协议的报文能够被正确的路由吗?Echo RequestEcho ReplyNetwork Layer测试网络的连接状况Router ping 172.16.101.1Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 172.16.101.1, timeout is 2 seconds:.!Success rate is

69、 80 percent, round-trip min/avg/max = 6/6/6 msRouterPing!Successful receipt of an echo reply .Times out waiting for datagram replyUDestination unreachable errorCCongestion-experienced packetIPing interrupted (for example, Ctrl-Shift-6 X)? ?Packet type unknownRouter# pingProtocol ip:Target IP address

70、: 192.168.101.162Repeat count 5:Datagram size 100:Timeout in seconds 2:Extended commands n: ySource address:Type of service 0:Set DF bit in IP header? no: yesData pattern 0xABCD:Loose, Strict, Record, Timestamp, Verbosenone:Sweep range of sizes n:Type escape sequence to abort.Sending 5, 100-byte ICM

71、P Echos to 192.168.101.162, timeout is 2 seconds:!Success rate is 100 percent (5/5), round-trip min/avg/max = 24/26/28 msRouter#Ping 命令支持多协议Ping(扩展)使用 trace 命令数据报文传输时经过那条路径?Rome172.16.33.5YorkLondon172.16.12.3Paris172.16.16.2Network LayerYork# trace ROMEType escape to abort.Tracing the route to ROME

72、 (172.16.33.5)1 LONDON (172.16.12.3) 1000 msec 8 msec 4 msec2 PARIS (172.16.16.2) 8 msec 8 msec 8 msec3 ROME (172.16.33.5) 8 msec 8 msec 4 msec York#通过端口地址表示数据到达的地点Router# trace aba.nyc.milType escape sequence to abort.Tracing the route to aba.nyc.mil (26.0.0.73) (172.16.1.6) 1000 msec 8 msec 4 mse

73、c2barrnet- (172.16.16.2) 8 msec 8 msec 8 msec3external-a-gateway.stanford.edu (192.42.110.225) 8 msec 4 msec 4 (131.119.254.6) 8 msec 8 msec 8 (131.119.3.8) 12 msec 12 msec 8 msec6moffett-fld-mb.in.mil (192.52.195.1) 216 msec 120 msec 132 msec7aba.nyc.mil (26.0.0.73) 412 msec * 664 msecIP TraceHTh

74、e probe was received by the router, but not forwarded, usually due to an access list.PThe protocol was unreachable.NThe network was unreachable.UThe port was unreachable.*Timeout.使用 show ip route 命令路由表正确吗?Paris# show ip routeCodes: I - IGRP derived, R - RIP derived, O - OSPF derived C - connected, S

75、 - static, E - EGP derived, B - BGP derived i - IS-IS derived, D - EIGRP derived * - candidate default route, IA - OSPF inter area route E1 - OSPF external type 1 route, E2 - OSPF external type 2 route L1 - IS-IS level-1 route, L2 - IS-IS level-2 route EX - EIGRP external routeGateway of last resort

76、 is not setI 144.253.0.0 100/1300 via 133.3.32.2 0:00:22 Ethernet1 131.108.0.0 is subnetted (mask is 255.255.255.0), 3 subnetsI 131.108.33.0 100/180771 via 131.108.16.2, 0:01:29, Ethernet1C 131.108.12.0 is directly connected, Ethernet0C 131.108.16.0 is directly connected, Ethernet1I 218.100.103.0 100/1200 via 133.3.32.2, 0:00:22, Ethernet1Network Layer问题讨论!