VLAN（Virtual Local Area Network）的中文名为"虚拟局域网"。虚拟局域网（VLAN）是一组逻辑上的设备和用户，这些设备和用户并不受物理位置的限制，可以根据功能、部门及应用等因素将它们组织起来，相互之间的通信就好像它们在同一个网段中一样，由此得名虚拟局域网。VLAN是一种比较新的技术，工作在OSI参考模型的第2层和第3层，一个VLAN就是一个广播域，VLAN之间的通信是通过第3层的路由器来完成的。与传统的局域网技术相比较，VLAN技术更加灵活，它具有以下优点： 网络设备的移动、添加和修改的管理开销减少；可以控制广播活动；可提高网络的安全性。VLAN 是指在一个物理网段内，进行逻辑的划分，划分成若干个虚拟局域网，VLAN做大的特性是不受物理位置的限制，可以进行灵活的划分。VLAN 具备了一个物理网段所具备的特性。相同 VLAN 内的主机可以相互直接通信，不同 VLAN 间的主机之间互相访问必须经路由设备进行转发，广播数据包只可以在本 VLAN 内进行广播，不能传输到其他 VLAN 中。Port VLAN 是实现 VLAN 的方式之一，它利用交换机的端口进行 VALN 的划分，一个端口只能属于一个 VLAN。Tag VLAN 是基于交换机端口的另一种类型，主要用于是交换机的相同 Vlan 内的主机之间可以直接访问，同时对不同 Vlan 的主机进行隔离。Tag VLAN 遵循IEEE802.1Q 协议的标准，在使用配置了 Tag VLAN 的端口进行数据传输时，需要在数据帧内添加 4 个字节的 8021.Q 标签信息，用于标示该数据帧属于哪个 VLAN,便于对端交换机接收到数据帧后进行准确的过滤。
新建 Packet Tracer 拓扑图；
划分 VLAN；
将端口划分到相应 VLAN 中；
设置 Tag VLAN Trunk 属性；
测试
实验设备
Switch_2960 2 台；PC 4 台；直连线
PC1
IP: 192.168.1.2
Submark: 255.255.255.0
Gateway: 192.168.1.1
PC2
IP: 192.168.1.3
Submark: 255.255.255.0
Gateway: 192.168.1.1
PC3
IP: 192.168.1.4
Submark: 255.255.255.0
Gateway: 192.168.1.1
PC4
IP: 192.168.1.5
Submark: 255.255.255.0
Gateway: 192.168.1.1
Switch1
en
conf t
vlan 2
exit
vlan 3
exit
inter fa 0/1
switch access vlan 2
exit
inter fa 0/2
switch access vlan 3
exit
inter fa 0/24
switch mode trunk
end
show vlan
Switch2
en
conf t
vlan 2
exit
vlan 3
exit
int fa 0/1
switch access vlan 2
exit
int fa 0/2
switch access vlan 3
exit
int fa 0/24
switch mode trunk
end
show vlan
PC1 ping PC2 timeout
PC1 ping PC3 Reply
Switch1
Switch>en
Switch#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#vlan 2
Switch(config-vlan)#exit
Switch(config)#vlan 3
Switch(config-vlan)#exit
Switch(config)#inter fa 0/1
Switch(config-if)#switch access vlan 2
Switch(config-if)#exit
Switch(config)#inter fa 0/2
Switch(config-if)#switch access vlan 3
Switch(config-if)#exit
Switch(config)#inter fa 0/24
Switch(config-if)#switch mode trunk
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/24, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/24, changed state to up
Switch(config-if)#end
Switch#
%SYS-5-CONFIG_I: Configured from console by console
Switch#show vlan
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active 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, Gig1/1, Gig1/2
2 VLAN0002 active Fa0/1
3 VLAN0003 active Fa0/2
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1 enet 100001 1500 - - - - - 0 0
2 enet 100002 1500 - - - - - 0 0
3 enet 100003 1500 - - - - - 0 0
1002 fddi 101002 1500 - - - - - 0 0
--More--
Switch2
Switch>en
Switch#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#vlan 2
Switch(config-vlan)#exit
Switch(config)#vlan 3
Switch(config-vlan)#exit
Switch(config)#int fa 0/1
Switch(config-if)#switch access vlan 2
Switch(config-if)#exit
Switch(config)#int fa 0/2
Switch(config-if)#switch access vlan 3
Switch(config-if)#exit
Switch(config)#int fa 0/24
Switch(config-if)#switch mode trunk
Switch(config-if)#end
Switch#
%SYS-5-CONFIG_I: Configured from console by console
Switch#show vlan
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active 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, Gig1/1, Gig1/2
2 VLAN0002 active Fa0/1
3 VLAN0003 active Fa0/2
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1 enet 100001 1500 - - - - - 0 0
2 enet 100002 1500 - - - - - 0 0
3 enet 100003 1500 - - - - - 0 0
1002 fddi 101002 1500 - - - - - 0 0
--More--
PC>ipconfig
IP Address......................: 192.168.1.2
Subnet Mask.....................: 255.255.255.0
Default Gateway.................: 192.168.1.1
PC>ping 192.168.1.3
Pinging 192.168.1.3 with 32 bytes of data:
Request timed out.
Request timed out.
Ping statistics for 192.168.1.3:
Packets: Sent = 2, Received = 0, Lost = 2 (100% loss),
Control-C
^C
PC>ping 192.168.1.4
Pinging 192.168.1.4 with 32 bytes of data:
Reply from 192.168.1.4: bytes=32 time=16ms TTL=128
Reply from 192.168.1.4: bytes=32 time=17ms TTL=128
Reply from 192.168.1.4: bytes=32 time=15ms TTL=128
Reply from 192.168.1.4: bytes=32 time=18ms TTL=128
Ping statistics for 192.168.1.4:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 15ms, Maximum = 18ms, Average = 16ms
PC>ipconfig
IP Address......................: 192.168.1.3
Subnet Mask.....................: 255.255.255.0
Default Gateway.................: 192.168.1.1
PC>ping 192.168.1.4
Pinging 192.168.1.4 with 32 bytes of data:
Request timed out.
Ping statistics for 192.168.1.4:
Packets: Sent = 2, Received = 0, Lost = 2 (100% loss),
Control-C
^C
PC>ping 192.168.1.5
Pinging 192.168.1.5 with 32 bytes of data:
Reply from 192.168.1.5: bytes=32 time=16ms TTL=128
Reply from 192.168.1.5: bytes=32 time=15ms TTL=128
Reply from 192.168.1.5: bytes=32 time=16ms TTL=128
Reply from 192.168.1.5: bytes=32 time=15ms TTL=128
Ping statistics for 192.168.1.5:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 15ms, Maximum = 16ms, Average = 15ms
