4.1.5数据链路层解析

数据链路层解析
数据链路层解析
案例1：MAC地址表及邻居信息查看
案例2：配置接口速率及双工模式
案例3：配置交换机管理IP
1 案例1：MAC地址表及邻居信息查看
1.1 问题
本例要求为修改计算机名并加入工作组：
1）查看交换机MAC地址表
2）查看CISCO设备邻居信息
1.2 方案
网络拓扑，如图-1所示。
![](/media/202202/1_1645182811.png)
图-1
1.3 步骤
实现此案例需要按照如下步骤进行。
步骤一：查看交换机sw1的mac地址表
1）在PC1上ping PC2:192.168.1.2：
PC>ipconfig /all
FastEthernet0 Connection:(default port)
Connection-specific DNS Suffix..:
Physical Address................: 00E0.B079.7815
Link-local IPv6 Address.........: FE80::2E0:B0FF:FE79:7815
IP Address......................: 192.168.1.1
Subnet Mask.....................: 255.255.255.0
Default Gateway.................: 0.0.0.0
DNS Servers.....................: 0.0.0.0
DHCP Servers....................: 0.0.0.0
DHCPv6 Client DUID..............: 00-01-00-01-E3-E0-53-04-00-E0-B0-79-78-15
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=1ms TTL=128
Reply from 192.168.1.2: bytes=32 time=0ms TTL=128
Reply from 192.168.1.2: bytes=32 time=1ms 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 = 1ms, Average = 0ms
2）查看PC2的IP信息
PC>ipconfig /all
FastEthernet0 Connection:(default port)
Connection-specific DNS Suffix..:
Physical Address................: 0003.E49E.6445
Link-local IPv6 Address.........: FE80::203:E4FF:FE9E:6445
IP Address......................: 192.168.1.2
Subnet Mask.....................: 255.255.255.0
Default Gateway.................: 0.0.0.0
DNS Servers.....................: 0.0.0.0
DHCP Servers....................: 0.0.0.0
DHCPv6 Client DUID..............: 00-01-00-01-DB-A7-C6-5E-00-03-E4-9E-64-45
3）在查看交换机sw1的mac地址表
Switch#hostname SW1
SW1#show mac-address-table
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
1 0003.e49e.6445 DYNAMIC Fa0/2
1 0010.1148.9309 DYNAMIC Fa0/24
1 00e0.b079.7815 DYNAMIC Fa0/1
步骤二：查看交换机sw1邻居信息
1）更改交换机sw2的主机名
Switch>enable
SW2#configure terminal
SW2(config)#hostname SW2
SW2(config)#
2）进入交换机SW1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
SW2 Fas 0/24 174 S 2950 Fas 0/9
案例2：配置接口速率及双工模式
2.1 问题
配置交换机接口双工模式为半双工，端口速率为10M并查看
2.2 方案
网络拓扑图如图-2
![](/media/202202/2_1645182890.png)
图-2
2.3 步骤
实现此案例需要按照如下步骤进行
步骤一：配置交换机接口模式
Switch>enable
Switch#configure terminal
Switch(config)#interface fastEthernet 0/24
Switch(config-if)#duplex half
Switch(config-if)#speed 10
Switch#show interfaces fastEthernet 0/24
FastEthernet0/24 is up, line protocol is up (connected)
Hardware is Lance, address is 00d0.5807.8301 (bia 00d0.5807.8301)
BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation 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 00:00:08, output 00:00:05, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue :0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
956 packets input, 193351 bytes, 0 no buffer
Received 956 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
2357 packets output, 263570 bytes, 0 underruns
0 output errors, 0 collisions, 10 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Switch#
最长 = 0ms，平均 = 0ms
3 案例3：配置交换机管理IP
3.1 问题
配置交换机管理IP为192.168.1.1 ，默认网关为192.168.1.100
3.2 方案
网络拓扑图如图-3

![](/media/202202/3_1645182985.png)
图-3
3.3 步骤
实现此案例需要按照如下步骤进行
步骤一：配置交换机接口模式
1）配置路由器R1的接口IP作为192.168.1.0网段的网关地址
Router>enable
Router#configure terminal
Router(config)#interface fastEthernet 0/0
Router(config-if)#ip address 192.168.1.100
Router(config-if)#ip address 192.168.1.100 255.255.255.0
Router(config-if)#no shutdown
2）配置交换机管理IP和网关地址
Switch(config)#interface vlan 1
Switch(config-if)#ip address 192.168.1.1 255.255.255.0
Switch(config-if)#no shutdown
Switch(config-if)#exit
Switch(config)#ip default-gateway 192.168.1.100
3）用ping命令进行测试
PC>ipconfig
FastEthernet0 Connection:(default port)
Link-local IPv6 Address.........: FE80::200:CFF:FEE4:90B0
IP Address......................: 192.168.1.2
Subnet Mask.....................: 255.255.255.0
Default Gateway.................: 192.168.1.100
PC>ping 192.168.1.1
Pinging 192.168.1.1 with 32 bytes of data:
Request timed out.
Reply from 192.168.1.1: bytes=32 time=0ms TTL=255
Reply from 192.168.1.1: bytes=32 time=3ms TTL=255
Reply from 192.168.1.1: bytes=32 time=0ms TTL=255
Ping statistics for 192.168.1.1:
Packets: Sent = 4, Received = 3, Lost = 1 (25% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 3ms, Average = 1ms
PC>ping 192.168.1.100
Pinging 192.168.1.100 with 32 bytes of data:
Reply from 192.168.1.100: bytes=32 time=50ms TTL=255
Reply from 192.168.1.100: bytes=32 time=0ms TTL=255
Reply from 192.168.1.100: bytes=32 time=0ms TTL=255
Reply from 192.168.1.100: bytes=32 time=0ms TTL=255
Ping statistics for 192.168.1.100:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 50ms, Average = 12ms