1.交换和交换机

1、交换和思科的Catalyst交换机, 2002, Cisco Systems, Inc. All rights reserved.,2,基本二层交换机和桥的功能,地址学习 转发/过滤决定 回路避免,以太网交换机和桥,Cut-Through 交换机检测到目标地址后即转发帧,Fragment-Free 片断转发 (直通转发的修订版)Cat1900 的缺省模式 交换机检测到帧的前64字节后即转发,Store and Forward 完整地收到帧并检查无错后才转发,帧交换方式,存贮转发,帧交换方式,MAC 地址表,最初开机时MAC地址表是空的,地址学习,主机A发送数据帧给主机C 交换机通过学习数据帧的

2、源MAC地址，记录下主机A的MAC地址 对应端口E0 该数据帧转发到除端口E0以外的其它所有端口 (不清楚目标主机的单点传送用泛洪方式),地址学习 (Cont.),主机D发送数据帧给主机C 交换机通过学习数据帧的源MAC地址，记录下主机D的MAC地址对应端口E03 该数据帧转发到除端口E3以外的其它所有端口 (不清楚目标主机的单点传送用泛洪方式),过滤帧,交换机A发送数据帧给主机C 在地址表中有目标主机，数据帧不会泛洪而直接转发,过滤帧（Cont.）,站A发送帧给站 交换机在MAC表中有站B的地址.,广播帧和多点传送帧,主机D发送广播帧或多点帧 广播帧或多点帧泛洪到除源端口外的所有端口,系统启

3、动例程初始化交换机软件 初始化启动使用默认的配置参数.,交换机的初始化启动,启动交换机前检查连线和控制台连接,电源线接入交换机电源插槽,观察启动顺序 LED灯 IOS软件输出内容,Catalyst 2950 Switch LED 指示,交换机的指示灯,交换机POST时端口 LED灯状态,1. 交换机启动，所有的端口LED灯变绿. 2. 测试结束后所有端口LED 灯熄灭. 3. 如果测试失败, LED 灯变为琥珀色. 4. 任何测试项目失败, 系统LED 灯都变为琥珀色. 5. 如果测试成功, POST结束. 6. POST结束时, LED闪烁后熄灭.,Catalyst 2950 Switch初

4、始化启动输出,- System Configuration Dialog - At any point you may enter a question mark ? for help. Use ctrl-c to abort configuration dialog at any prompt. Default settings are in square brackets . Continue with configuration dialog? yes/no: yes Enter IP address: ip_address Enter IP netmask: ip_netmask Wo

5、uld you like to enter a default gateway address? yes: yes IP address of the default gateway: ip_address Enter a host name: host_name Enter enable secret: secret_password Would you like to configure a Telnet password? yes yes Enter Telnet password: telnet_password Would you like to enable as a cluste

6、r command switch? no Enter cluster name: cls_name,登录到交换机后输入使能密码,上下文敏感帮助,控制台错误信息指示,指出任何交换机命令问题以便修改更正输入的命令,容许召回较长的、复杂的命令或回顾、修改、免重新输入使用过的命令,命令历史缓存器,提供针对命令的补全、参数列表,交换机命令行帮助方式,配置模式: 全局配置模式 wg_sw_a#configure terminal wg_sw_a(config)# 接口配置模式 wg_sw_a(config)#interface e0/1 wg_sw_a(config-if)#,配置交换机,设置交换机的本地

7、识别名,配置交换机的辨别名,查看交换机初始化启动状态,wg_sw_a#show version,显示系统硬件、软件版本，名字、配置文件来源和系统引导影像文件,wg_sw_a#show running-configuration,显示交换机当前活动的配置文件,wg_sw_a#show interfaces,显示交换机所有配置接口的统计,wg_sw_a#show ip,显示交换机IP地址、子网掩码、默认网关等,交换机 show version 命令,wg_sw_a#show version Cisco Catalyst 1900/2820 Enterprise Edition Software V

8、ersion V8.01.01 written from 171.068.229.225 Copyright (c) Cisco Systems, Inc. 1993-2001 wg_sw_c uptime is 15day(s) 21hour(s) 53minute(s) 11second(s) cisco Catalyst 1900 (486sxl) processor with 2048K/1024K bytes of memory Hardware board revision is 5 Upgrade Status: No upgrade currently in progress.

9、 Config File Status: No configuration upload/download is in progress 27 Fixed Ethernet/IEEE 802.3 interface(s) Base Ethernet Address: 00-50-BD-73-E2-C0,wg_sw_a#show interfaces ethernet 0/1 Ethernet 0/1 is Enabled Hardware is Built-in 10Base-T Address is 0050.BD73.E2C1 MTU 1500 bytes, BW 10000 Kbits

10、802.1d STP State: Forwarding Forward Transitions: 1 Port monitoring: Disabled Unknown unicast flooding: Enabled Unregistered multicast flooding: Enabled Description: Duplex setting: Half duplex Back pressure: Disabled -More-,交换机show interfaces 命令, 2002, Cisco Systems, Inc. All rights reserved.,24,Co

11、nfiguring a Catalyst Switch,IP address: 0.0.0.0 CDP: enabled 100baseT port: 自动协商 双工模式 Spanning tree: enabled Console password: 无,Catalyst 1900 and 2950 默认配置,wg_sw_2950#show run Building configuration. Current configuration: ! ! interface FastEthernet0/1 ! interface FastEthernet0/2,wg_sw_2950#show sp

12、antree Interface Fa0/1 (port 7) in Spanning tree 1 is FORWARDING Port path cost 19, Port priority 128 Designated root has priority 32768, address 0008.a445.c980 Designated bridge has priority 32768, address 0008.a445.c980 Designated port is 7, path cost 0 Timers: message age 0, forward delay 0, hold

13、 0 BPDU: sent 8316, received 4,wg_sw_2950#show vlan VLAN Name Status Ports - - - - 1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4, Fa0/5, Fa0/6, Fa0/7, Fa0/8, Fa0/9, Fa0/10, Fa0/11, Fa0/12, Fa0/13, Fa0/14, Fa0/15, Fa0/16, Fa0/17, Fa0/18, Fa0/19, Fa0/20, Fa0/21, Fa0/22, Fa0/23, Fa0/24,Catalyst 2950交换机上的

14、端口名,wg_sw_1900(config)#ip address 10.5.5.11 255.255.255.0,wg_sw_1900(config)#ip address ip_address mask,配置交换机的IP地址,配置交换机的IP地址和子网掩码,Catalyst 1900,wg_sw_2950(config)#interface vlan 1 wg_sw_2950(config-if)#ip address 10.5.5.11 255.255.255.0,wg_sw_2950(config-if)#ip address ip_address mask,在交换机的VLAN1接口上

15、配置IP地址及子网掩码,Catalyst 2950,wg_sw_a(config)# ip default-gateway ip address,配置交换机的默认网关（Catalyst 1900 和 2950 switches ）,配置交换机的默认网关,wg_sw_a(config)#ip default-gateway 10.5.5.3,查看交换机的IP地址,Catalyst 1900,Catalyst 2950,wg_sw_1900#show ip IP address: 10.5.5.11 Subnet mask: 255.255.255.0 Default gateway: 10.5.

16、5.3 Management VLAN: 1 wg_sw_a#,wg_sw_2950#show interface vlan 1 Vlan1 is up, line protocol is up Hardware is Cat5k Virtual Ethernet, address is 0010.f6a9.9800 (bia 0010.f6a9.9800) Internet address is 172.16.80.79/24 Broadcast address is 255.255.255.255 . . . wg_sw_2950#,双工概览,半双工Half Duplex (CSMA/CD

17、) 单向数据流（Unidirectional data flow） 冲突概率高 Hubs 连通,全双工Full Duplex 点对点连接 连接在专门的交换机端口 要求两端都具有全双工支持 无冲突 取消冲突检测电路,wg_sw_1900(config)#interface e0/1 wg_sw_1900(config-if)#duplex auto | full | full-flow-control | half,设置双工选项,Catalyst 1900,Catalyst 2950,wg_sw_2950(config)#interface fe0/1 wg_sw_2950(config-if)

18、#duplex auto | full | half,查勘双工选项,Switch#show interfaces fastethernet0/3 FastEthernet0/3 is up, line protocol is down Hardware is Fast Ethernet, address is 0000.0000.0003 (bia 0000.0000.0003) MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation

19、ARPA, loopback not set Keepalive set (10 sec) Half-duplex, 10Mb/s input flow-control is off, output flow-control is off ARP type: ARPA, ARP Timeout 04:00:00 Last input never, output never, output hang never Last clearing of show interface counters never Queueing strategy: fifo Output queue 0/40, 0 d

20、rops; input queue 0/75, 0 drops 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 input packets with dribble c

21、ondition detected 0 packets output, 0 bytes, 0 underruns 0 output errors, 0 collisions, 2 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out,wg_sw_1900#show mac-address-table Number of permanent addresses : 0 N

22、umber of restricted static addresses : 0 Number of dynamic addresses : 6 Address Dest Interface Type Source Interface List - 00E0.1E5D.AE2F Ethernet 0/2 Dynamic All 00D0.588F.B604 FastEthernet 0/26 Dynamic All 00E0.1E5D.AE2B FastEthernet 0/26 Dynamic All 0090.273B.87A4 FastEthernet 0/26 Dynamic All

23、00D0.588F.B600 FastEthernet 0/26 Dynamic All 00D0.5892.38C4 FastEthernet 0/27 Dynamic All,管理MAC地址表,Catalyst 1900,Catalyst 2950,wg_sw_1900(config)#mac-address-table permanent 2222.2222.2222 ethernet 0/3 wg_sw_1900#show mac-address-table Number of permanent addresses : 1 Number of restricted static ad

24、dresses : 0 Number of dynamic addresses : 4 Address Dest Interface Type Source Interface List - 00E0.1E5D.AE2F Ethernet 0/2 Dynamic All 2222.2222.2222 Ethernet 0/3 Permanent All 00D0.588F.B604 FastEthernet 0/26 Dynamic All 00E0.1E5D.AE2B FastEthernet 0/26 Dynamic All 00D0.5892.38C4 FastEthernet 0/27

25、 Dynamic All,wg_sw_1900(config)#mac-address-table permanent mac-address type module/port,配置永久MAC地址,wg_sw_2950(config)#mac-address-table static mac_addr vlan vlan_id interface int1 int2 . int15,Catalyst 1900 and 2950,Catalyst 2950 only,wg_sw_2950#mac-address-table secure 0003.3333.3333 fa 0/1 vlan 1

26、wg_sw_2950#show mac-address-table Dynamic Address Count: 1 Secure Address Count: 1 Static Address (User-defined) Count: 1 System Self Address Count: 25 Total MAC addresses: 28 Maximum MAC addresses: 8192 Non-static Address Table: Destination Address Address Type VLAN Destination Port - - - - 0050.0f02.3372 Dynamic 1 FastEthernet0/2 0003.3333.3333 Secure 1 FastEthernet0/1 Static Address Table: Destination Address VLAN Input Port Output Ports - - - - 2222.2222.2222 1 ALL Fa0/1,在 Catalyst 2950上配置受限静态MAC地址,wg_sw_2950(config)#mac-addre