利用三层交换机实现不同VLAN间的访问

【实验名称】
VLAN/802.1Q-VLAN间的通信
【实验目的】
通过三层交换机实现VLAN间互相通信
【实验功能】
使在同一VLAN里的计算机系统能跨交换机进行相互通信，而在不同VLAN里的计算机系统也能进行相互通信
【实验设备】
三层交换机（1台）、普通可网管交换机（1台）、直连线（3条）
【实验拓扑】




【实验步骤】
三层交换机：3Switch1
Switch>enable
Switch#configure terminal
Switch(config)#vlan 10
Switch(config-vlan)#exit
Switch(config)#vlan 20
Switch(config-vlan)#exit
Switch(config)#interface fastEthernet 0/5
Switch(config-if)#switchport access vlan 10
Switch(config-if)#exit
Switch(config)#interface fastEthernet 0/15
Switch(config-if)#switchport access vlan 20
Switch(config-if)#exit
Switch(config)#interface fastEthernet 0/24
Switch(config-if)#switchport mode trunk

二层交换机：Switch1
Switch>enable
Switch#configure terminal
Switch(config)#vlan 10
Switch(config-vlan)#exit
Switch(config)#interface fastEthernet 0/5
Switch(config-if)#switchport access vlan 10
Switch(config)#interface fastEthernet 0/24
Switch(config-if)#switchport mode trunk
现在我们把192.168.10.1 、192.168.10.2分别给VLAN10 里的2个PC
192.168.10.3 给VLAN 20的 PC
此时发现
PC>ping 192.168.10.2
Pinging 192.168.10.2 with 32 bytes of data:
Reply from 192.168.10.2: bytes=32 time=93ms TTL=128
Reply from 192.168.10.2: bytes=32 time=78ms TTL=128
Reply from 192.168.10.2: bytes=32 time=93ms TTL=128
Reply from 192.168.10.2: bytes=32 time=94ms TTL=128
Ping statistics for 192.168.10.2:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 78ms, Maximum = 94ms, Average = 89ms
PC>ping 192.168.10.3
Pinging 192.168.10.3 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Ping statistics for 192.168.10.3:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
相同VLAN可以通信 不同VLAN 不可通信！
本章节关键就在这里！
继续在三层交换机配置
Switch(config)#interface vlan 10 （进入虚拟VLAN接口）
Switch(config-if)#no shutdown
Switch(config-if)#ip address 192.168.10.254 255.255.255.0 （配置IP地址 即VLAN10网关）
Switch(config-if)#exit
Switch(config)#interface vlan 20
Switch(config-if)#no shutdown
Switch(config-if)#ip address 192.168.20.254 255.255.255.0

这时把VLAN20的PC IP改成192.168.20.1 因为要和网关一个网段 （开始配置是为了证明不通VLAN 就算一个网段IP亦不可通）
VLAN10 的PC 网关改为192.168.10.254 VLAN 20PC网关 192.168.20.254
此时：
PC>ping 192.168.10.1
Pinging 192.168.10.1 with 32 bytes of data:
Reply from 192.168.10.1: bytes=32 time=62ms TTL=127
Reply from 192.168.10.1: bytes=32 time=63ms TTL=127
Reply from 192.168.10.1: bytes=32 time=31ms TTL=127
Reply from 192.168.10.1: bytes=32 time=62ms TTL=127
Ping statistics for 192.168.10.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 31ms, Maximum = 63ms, Average = 54ms
PC>ping 192.168.10.2
Pinging 192.168.10.2 with 32 bytes of data:
Reply from 192.168.10.2: bytes=32 time=94ms TTL=127
Reply from 192.168.10.2: bytes=32 time=93ms TTL=127
Reply from 192.168.10.2: bytes=32 time=78ms TTL=127
Reply from 192.168.10.2: bytes=32 time=94ms TTL=127
Ping statistics for 192.168.10.2:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 78ms, Maximum = 94ms, Average = 89ms
全网互通！