Basic configuration: cisco switch configuration vlan (1)

Vlan configuration ideas: access, Trunk)

1) create a Vlan

Configure static VLAN on an IOS-based switch:

 
 

  
  
Switch # vlan database
  
  
 
  
  
Switch (vlan) # vlan-num name vlan-name
  
  
 
  
  
Switch (vlan) # exit
  
  
 
  
  
Switch # configure teriminal
  
  
 
  
  
Switch (config) # interface module/number
  
  
 
  
  
Switch (config-if) # switchport mode access // set the port mode to access
  
  
 
  
  
Switch (config-if) # switchport access vlan-num // set the vlan to which the port belongs
  
  
 
  
  
Switch (config-if) # end
 
 

Verify Configuration: show vlan

2) configure the trunk Link

The trunk is a point-to-point link between two catalyst Switch ports or between the catalyst Switch and the router. Trunk links can carry multiple VLANs.

Configure trunk links on IOS-based switches

 
 

  
  
Switch (config) # interface mod/port
  
  
 
  
  
Switch (config-if) # switchport mode trunk // you can specify trunk as the port mode.
  
  
 
  
  
Switch (config-if) # switchport trunk encapsulation {isl | dotlq} // you can specify the frames encapsulated by the trunk.
  
  
 
  
  
Switch (config-if) # switchport trunk allowed vlan remove vlan-list // allow those VLANs to pass through trunk
  
  
 
  
  
Appendix: switchport trunk allowed vlan {add | all | unique T | remove} vlan-list)
 
 

No switchport

No switchport // The physical port is changed to a layer-3 Port, that is, the layer-3 port is used as the port on the router. After a port is configured as a layer-3 Port, an IP address can be allocated to the port, of course, you can still connect to a PC ,. Router port: A physical port is a port generated by the no switchport command in the port configuration status. IP addresses are required for all layer-3 routing ports for Route exchange.

Configuration example:

 
 

  
  
Switch# configure terminal  
  
  
 
  
  
Switch(config)# interface gigabitethernet0/2  
  
  
 
  
  
Switch(config-if)# no switchport  
  
  
 
  
  
Switch(config-if)# ip address 192.20.135.21 255.255.255.0  
  
  
 
  
  
Switch(config-if)# no shutdown  
  
  
 
  
  
Switch(config-if)# end 
 
 

Appendix: show interfaces [interface-id] switchport // display the status of the L2 port, which can be used to determine whether the port is a L2 or L3 port. Eg: Switch # show interfaces fastethernet 0/1 switchport

There is still a lot of content about VLAN configuration. This article is just a part of it and I hope you can master it more.