| 某一公司內財務部、銷售部的 PC 通過 2 臺交換機實現通信；要求財務部和銷售部的 PC 可以互通，但為了數據安全起見，銷售部和財務部需要進行互相隔離，現要在交換機上做適當配置來實現這一目標。 |
VLAN（Virtual Local Area Network）的中文名為"虛擬局域網"。
虛擬局域網（VLAN）是一組邏輯上的設備和用戶，這些設備和用戶并不受物理位置的限制，可以根據功能、部門及應用等因素將它們組織起來，相互之間的通信就好像它們在同一個網段中一樣，由此得名虛擬局域網。VLAN是一種比較新的技術，工作在OSI參考模型的第2層和第3層，一個VLAN就是一個廣播域，VLAN之間的通信是通過第3層的路由器來完成的。與傳統的局域網技術相比較，VLAN技術更加靈活，它具有以下優點：網絡設備的移動、添加和修改的管理開銷減少；可以控制廣播活動；可提高網絡的安全性。
VLAN 是指在一個物理網段內，進行邏輯的劃分，劃分成若干個虛擬局域網，VLAN做大的特性是不受物理位置的限制，可以進行靈活的劃分。VLAN 具備了一個物理網段所具備的特性。相同 VLAN 內的主機可以相互直接通信，不同 VLAN 間的主機之間互相訪問必須經路由設備進行轉發，廣播數據包只可以在本 VLAN 內進行廣播，不能傳輸到其他 VLAN 中。
Port VLAN 是實現 VLAN 的方式之一，它利用交換機的端口進行 VALN 的劃分，一個端口只能屬于一個 VLAN。
Tag VLAN 是基于交換機端口的另一種類型，主要用于是交換機的相同 Vlan 內的主機之間可以直接訪問，同時對不同 Vlan 的主機進行隔離。Tag VLAN 遵循IEEE802.1Q 協議的標準，在使用配置了 Tag VLAN 的端口進行數據傳輸時，需要在數據幀內添加 4 個字節的 8021.Q 標簽信息，用于標示該數據幀屬于哪個 VLAN,便于對端交換機接收到數據幀后進行準確的過濾。
新建 Packet Tracer 拓撲圖；
劃分 VLAN；
將端口劃分到相應 VLAN 中；
設置 Tag VLAN Trunk 屬性；
測試
實驗設備
Switch_2960 2 臺；PC 4 臺；直連線
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
本文原創地址：https://www.linuxprobe.com/switch-vlan-configuration.html 編輯：傳棋，審核員：逄增寶
