SVI (switched virtual interface)
If you have Multilayer switch than router is not required for Inter VLAN Routing, because that switch can work as a router. you have to create interfaces only for existing VLANs. In this technique the interfaces created for existing VLANs are known as SVI (Switched Virtual Interfaces).
(you can create interface for any VLAN, but those interfaces will up which will be created for existing VLAN, here you have to remember that you cannot up interfaces with no shutdown command)
Lab SVI
We have to perform four steps:
- Create VLANs
- Assign membership of those VLANs to ports
- Enable ip routing
- Create interfaces
Switch>
Switch>en
Switch#config
Configuring from terminal, memory, or network [terminal]?
Enter configuration commands, one per line. End with CNTL/Z.
Step 1:
Switch(config)#vlan 20
Switch(config-vlan)#name IT
Switch(config-vlan)#exit
Switch(config)#vlan 30
Switch(config-vlan)#name HR
Switch(config-vlan)#exit
Step 2:
Switch(config)#int fastEthernet 0/1
Switch(config-if)#switchport mode access
Switch(config-if)#switchport access vlan 20
Switch(config-if)#exit
Switch(config)#int fa 0/11
Switch(config-if)#switchport mode access
Switch(config-if)#switchport access vlan 30
Switch(config-if)#exit
Step 3:
Switch(config)#ip routing
Step 4:
Switch(config)#int vlan 20
Switch(config-if)#
%LINK-5-CHANGED: Interface Vlan20, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan20, changed state to up
Switch(config-if)#ip address 20.1.1.1 255.0.0.0
Switch(config-if)#exit
Switch(config)#int vlan 30
Switch(config-if)#
%LINK-5-CHANGED: Interface Vlan30, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan30, changed state to up
Switch(config-if)#ip address 30.1.1.1 255.0.0.0
Switch(config-if)#exit
Switch(config)#exit
Switch#
%SYS-5-CONFIG_I: Configured from console by console
Switch#wr
Building configuration…
[OK]
Switch#show ip route (with this command you will see interfaces directly connected)
C 20.0.0.0/8 is directly connected, Vlan20 (directly connected)
C 30.0.0.0/8 is directly connected, Vlan30 (directly connected)
