交换机是目前用于组建局域网的主要设备，交换机根据MAC地址表实现数据帧的转发，通过查看MAC地址表更加有利于交换机工作原理的理解；通过查看CISCO设备邻居信息来了解网络拓扑；通过telnet方式远程访问、配置交换机，这种方式要求此交换机已配置有IP地址。 查看交换机MAC地址表 查看CISCO设备邻居信息 交换机地址配置及默认网关 网络拓扑，如图-1所示。 图－１
步骤一：查看交换机MAC地址表
1）按拓扑配置PC1及PC2的IP地址并查看，如下所示：
PC>ipconfig
FastEthernet0 Connection:(default port)
Link-local IPv6 Address…: FE80::2D0:97FF:FED2:2DB0 //PC1的MAC地址 IP Address…: 192.168.1.1 //PC1的IP地址 Subnet Mask…: 255.255.255.0 Default Gateway…: 0.0.0.0
PC>ipconfig
FastEthernet0 Connection:(default port)
Link-local IPv6 Address…: FE80::2D0:BCFF:FE56:AB31 //PC2的MAC地址 IP Address…: 192.168.1.2 //PC2的IP地址 Subnet Mask…: 255.255.255.0 Default Gateway…: 0.0.0.0 2）PC1通过ping命令测试与PC2的连通性： PC>ping 192.168.1.2
Pinging 192.168.1.2 with 32 bytes of data:
Reply from 192.168.1.2: bytes=32 time=2ms TTL=128 Reply from 192.168.1.2: bytes=32 time=0ms TTL=128 Reply from 192.168.1.2: bytes=32 time=3ms TTL=128 Reply from 192.168.1.2: bytes=32 time=0ms TTL=128
Ping statistics for 192.168.1.2: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 0ms, Maximum = 3ms, Average = 1ms
3）查看交换机MAC地址表：
Switch#show mac-address-table
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
1 00d0.97d2.2db0 DYNAMIC Fa0/1
1 00d0.bc56.ab31 DYNAMIC Fa0/2
步骤二：查看CISCO设备邻居信息
1）配置路由器接口IP：
Router>enable Router#configure terminal Router(config)#interface fastEthernet 0/0 Router(config-if)#ip address 192.168.1.254 255.255.255.0 Router(config-if)#no shutdown
2）进入交换机特权模式通过命令查看CISCO设备邻居信息：
Switch#show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
Router Fas 0/3 179 R C2600 Fas 0/0
步骤三：交换机地址配置及默认网关
1）配置IP地址（192.168.1.10/24）
执行“int vlan1”（或interface vlan1）指令进入交换机的vlan1接口配置，再执行“ip add 192.168.1.10 255.255.255.0”配置IP地址（ip add指令相当于ip address），执行“no shutdown”启用此接口，如下所示：
Switch(config)# int vlan1 //进入vlan1接口
Switch(config-if)# ip add 192.168.1.10 255.255.255.0 //配置IP地址
Switch(config-if)# no shutdown //启用接口
%LINK-5-CHANGED: Interface Vlan1, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to up
2）进入交换机全局配置模式配置交换机默认网关地址：
Switch#configure terminal
Switch(config)#ip default-gateway 192.168.1.254
3）确认当前的运行配置
直接执行“end”指令返回特权模式：
Switch(config-if)# end //返回特权模式
Switch#
%SYS-5-CONFIG_I: Configured from console by console
4）确认vlan1接口的IP及网关地址信息：
Switch#show running-config
Building configuration...
Current configuration : 1026 bytes
!
version 12.1
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Switch
!
!
!
spanning-tree mode pvst
!
interface FastEthernet0/1
!
interface FastEthernet0/2
!
interface FastEthernet0/3
!
interface FastEthernet0/4
interface FastEthernet0/5
!
interface FastEthernet0/6
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface FastEthernet0/9
!
interface FastEthernet0/10
!
interface FastEthernet0/11
!
interface FastEthernet0/12
!
interface FastEthernet0/13
!
interface FastEthernet0/14
!
interface FastEthernet0/15
!
interface FastEthernet0/16
!
interface FastEthernet0/17
!
interface FastEthernet0/18
!
interface FastEthernet0/19
!
interface FastEthernet0/20
!
interface FastEthernet0/21
!
interface FastEthernet0/22
!
interface FastEthernet0/23
!
interface FastEthernet0/24
!
interface Vlan1
ip address 192.168.1.10 255.255.255.0 //IP地址与配置一致
!
ip default-gateway 192.168.1.254 //网关地址与配置一致
!
!
!
!
line con 0
!
line vty 0 4
login
line vty 5 15
login
!
!
end
