1. VLAN ROUTING How can we route traffic between vlans ? By Default Vlans isolate them selves. To Route Traffic we can use: 1. Router: A Router connected with a switch. On this router we can create sub- interfaces to route traffic. It’s very easy to setup, but disadvantage is that the traffic comes and goes from the same link. Also if the router fails so does the link thus a single point of failure. Routing is delayed causing slowing down all traffic as switches are must faster than the routers

2. VLAN ROUTING Configuration: Lets say we have two vlans 10 & 20 and we need routing in between them: Note: First Setup Trunk between Switch and a Router: Configuration on Switch: Go to Switch: Switch(config) int fast 0/0  Switch(config-if) switchport trunk encapsulation dot1q  Switch(config-if) switchport mode trunk  Note: Trunks don’t appear when we use vlan show commands.

3. VLAN ROUTING Configuration on Router: Router(config)# int fast 0/0  Router(config-if)# no shutdown  Router(config-if)# exit  Now Create Sub-interface on Router {Let say No. 10} Router(config)# int fa 0/0.10  Router(config-subif)# encapsulation dot1Q 10  Now assigning the IP address to this Sub int Router(config-subif)# ip address 192.168.10.10 255.255.255.0  Router(config-subif)# exit 

4. VLAN ROUTING Configuration on Router: Now Lets Create Subinterface 20 for Vlan 20 Router(config)# int fa 0/0.20  Router(config-subif)# encapsulation dot1Q 20  Now assigning the IP address to this Sub interface Router(config-subif)# ip address 192.168.20.20 255.255.255.0  Router(config-subif)# exit  We can now see the addresses by command of show ip address Now Routing should work ! Now lets move to Faster Solution. Which is Layer 3 processing in a Switch know as Layer Three Switchinng.

5. VLAN ROUTING Multilayer Switches: They support Routing via SVI [Switched Virtual Interfaces]. They are just like sub-interface of router, they are virtual not physical. Configuration on Switch: First lets create SVI 10 on the Switch Switch(config) int vlan 10  Now lets assign the IP address Switch (config-if)# ip address 192.168.10.10 255.255.255.0  Switch(config-if)# no shutdown  Now for SVI 20 Switch (config)# int vlan 20  Switch (config-if)# ip address 192.168.20.20 255.255.255.0  Switch(config-if)# no shutdown  Now we can see both interfaces by typing show ip int br command

6. VLAN ROUTING Now to Route Traffic Between These two interfaces, we need to enable routing in the switch: Switch(config)# ip routing  Now we should be able to reach both vlan devices. Routed Ports: This is a second way of enabling routing in switch. Any physical interface on switch can be turned into a routed port. Meaning its not virtual but physical. Lets say we would like to convert the second port to a Routed port we would perform the following configuration:

7. VLAN ROUTING Configuration: Switch(config)# int fast 0/2  Switch (config-if)# no switchport This convert the port to routed port. Now we can assign the IP address To this interface. Switch(config-if)# ip address 192.168.10.10 255.255.255.0  Now we can check the connectivity with ping command. CEF is the hardware piece which fas up the routing process as without it Router is still slower than the switch. Thanks www.itpings.com Hyp3ri0n