Brief introduction of VLAN principle and specific experimental configuration

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VLAN brief introduction

VALN The benefits of

Specific experimental configuration

vlan Configuration command of  

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VLAN brief introduction

VLAN（Virtual Local Area Network） The Chinese name of " Virtual LAN ".

VLAN It means virtual LAN .VLAN You can ignore the physical location of the user , And according to the function 、 Application and other factors Logically divide users into working groups with relatively independent functions , Each user host is connected to a support VLAN The switch port of is not a hand VLAN. The same VLAN All members in share the broadcast , Form a broadcast domain , And different VLAN The broadcast information between them is isolated . such , Divide the whole network into several different broadcast domains （VLAN). Generally speaking , If one VLAN The workstation inside sends a broadcast , So this VLAN Inside Some workstations receive this broadcast , But the switch will not send broadcasts to other VLAN Any port on . If you want to send the broadcast to another VLAN port , Three layer switches are needed .

VALN The benefits of

Security

Enhance the security of LAN , User groups containing sensitive data can be isolated from the rest of the network , So as to reduce the possibility of disclosing confidential information . Different VLAN Messages in are isolated from each other during transmission , That is, a VLAN Users in cannot communicate with others VLAN Direct communication between users within , If different VLAN To communicate , You need to use layer 3 devices such as router or layer 3 switch .

flexibility

Improve the flexibility of network construction :VLAN Technology makes network design and deployment more flexible . Users in the same workgroup no longer need to be confined to the same geographical location .

Cut off the radio

When the switch is deployed VLAN after , Flooding of broadcast data is limited to VLAN Inside . utilize VLAN Technology can cut the network from a large broadcast domain to several smaller broadcast domains , Thus, the loss of bandwidth resources and equipment performance caused by flooding is reduced .

 

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Specific experimental configuration

vlan Configuration command of  

1、 Create... On the switch vlan,vlan Is numbered by 12 Bit binary structure （0-4095） among 1-4094 You can use , The default switch exists vlan1, And all interfaces are marked in vlan1

Create according to the experimental requirements vlan

[sw1]vlan 2

[sw1-vlan2]q

[sw1]vlan 3

[sw1-vlan3]q

2、 Divide the interfaces on the switch into corresponding interfaces vlan in

[sw1]interface Ethernet0/0/1     （ Divide an interface into corresponding vlan）

[sw1-Ethernet0/0/1]port link-type access   （ First, modify the interface to the access mode ）

[sw1-Ethernet0/0/1]port default vlan 2   （ Then divide the interface into corresponding vlan in ）

With LSW3 For example , take Ethernet0/0/1 Transfer in vlan2, take Ethernet0/0/2 Transfer in vlan3, And then look at it vlan Forms

You can see that the two interfaces have been successfully entered , Then complete the other two configurations in turn

3、trunk main rd ： It doesn't belong to any one vlan, Carry all vlan Traffic forwarding , Can mark （ encapsulation ） distinguish （ decapsulation ） Different vlan The label of .

[sw1]interface e0/0/5

[sw1-Ethernet0/0/5]port link-type trunk （ Modify the interface trunk Pattern ）

[sw1-Ethernet0/0/5]port trunk allow-pass vlan 2 to 3  

Follow this operation to complete the interface between the switch and the switch and the router  

4、 The sub interface of the router

[router]interface g0/0/0.1  （ Create sub interfaces ）

[router-GigabitEthernet0/0/0.1]dot1q termination vid 2   （ Define what it manages vlan）

[router-GigabitEthernet0/0/0.1]ip address 192.168.1.254 24

[router-GigabitEthernet0/0/0.1]arp broadcast enable    （ Open the sub interface ARP function ）

  Configure , Most of the requirements of the experiment have been completed , Only through DHCP Decentralization IP

After entering the router ：

[Huawei]dhcp enable  （ First open dhcp service ）

[Huawei]ip pool a           ( Create a “a” Of dhcp pond )

[Huawei-ip-pool-a]         

[Huawei-ip-pool-a]network 192.168.1.0 mask 255.255.255.0   （ Definition ip Address assignment range ）

[Huawei-ip-pool-a]gateway-list 192.168.1.1  ( The network segment gateway )

[Huawei-ip-pool-a]dns-list 192.168.1.20 114.114.114.114  (DNS Server address )

If it's Huawei equipment , You need to go to the corresponding port to start DHCP

[Huawei]interface g0/0/0

[Huawei-GigabitEthernet0/0/0]dhcp select global

Finally, just write the route to the other network segment on the two routers to complete the experiment .