一、實驗目標
- 理解虛擬 LAN(VLAN)基本原理；
- 掌握一般交換機按端口划分 VLAN的配置方法；
- 掌握Tag VLAN配置方法。
二、實驗背景
某一公司內財務部、銷售部的PC通過2台交換機實現通信；要求財務部和銷售部內的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隔離，現要在交換機上做適當配置來實現這一目的。
三、技術原理
- VLAN是指在一個物理網段內，進行邏輯的划分，划分成若干個虛擬局域網。VLAN最大的特性是不受物理位置的限制，可以進行靈活的划分。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由路由設備進行轉發。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VLAN的划分，一個端口只能屬於一個VLAN。
- Tag VLAN是基於交換機端口的另外一種類型，主要用於使交換機的相同VLAN內的主機之間可以直接訪問，同時對於不同VLAN的主機進行隔離。Tag VLAN遵循IEEE802.1Q協議的標准。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802.1Q標簽信息，用於標示該數據幀屬於哪個VLAN，便於對端交換機收到數據幀后進行准確的過濾。
四、實驗步驟
實驗拓撲
1、設置四台PC機IP地址如圖所示。
2、對交換機S1進行設置。
Switch>en
Switch#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S1 //設置主機名
S1(config)#vlan 2 //划分VLAN 2
S1(config-vlan)#exit
S1(config)#vlan 3 //划分VLAN 3
S1(config-vlan)#exit
S1(config)#interface fa0/1
S1(config-if)#switchport access vlan 2 //將fa0/1划分到VLAN 2
S1(config-if)#exit
S1(config)#interface fa0/2
S1(config-if)#switchport access vlan 3 //將fa0/2划分到VLAN 3
S1(config-if)#exit
S1(config)#interface fa0/24 //設置fa0/24端口模式為trunk
S1(config-if)#switchport mode trunk
S1(config-if)#end
S1#
%SYS-5-CONFIG_I: Configured from console by console
S1#show vlan //查看VLAN划分情況
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 TranS1
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1 enet 100001 1500 - - - - - 0 0
2 enet 100002 1500 - - - - - 0 0
3 enet 100003 1500 - - - - - 0 0
1002 fddi 101002 1500 - - - - - 0 0
1003 tr 101003 1500 - - - - - 0 0
1004 fdnet 101004 1500 - - - ieee - 0 0
1005 trnet 101005 1500 - - - ibm - 0 0
Remote SPAN VLANs
------------------------------------------------------------------------------
Primary Secondary Type Ports
------- --------- ----------------- ------------------------------------------
S1#show running-config
Building configuration...
Current configuration : 1080 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname S1
!
!
!
interface FastEthernet0/1
switchport access vlan 2
!
interface FastEthernet0/2
switchport access vlan 3
!
interface FastEthernet0/3
!
......
!
interface FastEthernet0/24
switchport mode trunk
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Vlan1
no ip address
shutdown
!
!
line con 0
!
line vty 0 4
login
line vty 5 15
login
!
!
end
S1#
3、對交換機S2進行設置。
Switch>en
Switch#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S2
S2(config)#vlan 2
S2(config-vlan)#exit
S2(config)#vlan 3
S2(config-vlan)#exit
S2(config)#interface fa0/1
S2(config-if)#switchport access vlan 2
S2(config-if)#exit
S2(config)#interface fa0/2
S2(config-if)#switchport access vlan 3
S2(config-if)#exit
S2(config)#interface fa0/24
S2(config-if)#switchport mode trunk
S2(config-if)#end
S2#
%SYS-5-CONFIG_I: Configured from console by console
S2#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
1003 tr 101003 1500 - - - - - 0 0
1004 fdnet 101004 1500 - - - ieee - 0 0
1005 trnet 101005 1500 - - - ibm - 0 0
Remote SPAN VLANs
------------------------------------------------------------------------------
Primary Secondary Type Ports
------- --------- ----------------- ------------------------------------------
S2#show running-config
Building configuration...
Current configuration : 1080 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname S2
!
!
!
interface FastEthernet0/1
switchport access vlan 2
!
interface FastEthernet0/2
switchport access vlan 3
!
interface FastEthernet0/3
!
......
!
interface FastEthernet0/24
switchport mode trunk
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Vlan1
no ip address
shutdown
!
!
line con 0
!
line vty 0 4
login
line vty 5 15
login
!
!
end
S2#
五、驗證
打開PC1的Command Prompt
Packet Tracer PC Command Line 1.0
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. //不同VLAN間無法PING通
Request timed out.
Request timed out.
Request timed out.
Ping statistics for 192.168.1.3:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
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=172ms TTL=128 //相同VLAN可以PING通
Reply from 192.168.1.4: bytes=32 time=78ms TTL=128
Reply from 192.168.1.4: bytes=32 time=63ms TTL=128
Reply from 192.168.1.4: bytes=32 time=79ms 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 = 63ms, Maximum = 172ms, Average = 98ms