%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0.3, changed state to up %LINK-5-CHANGED: Interface GigabitEthernet0/0.3, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0.2, changed state to up %LINK-5-CHANGED: Interface GigabitEthernet0/0.2, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0.1, changed state to up %LINK-5-CHANGED: Interface GigabitEthernet0/0.1, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up %LINK-5-CHANGED: Interface GigabitEthernet0/0, changed state to up Now, let’s configure the router: R1(config)#int Gi0/0 Other ports were configured as access ports and placed into respective VLANs since they are connected to end devices. Notice how we’ve configured the Fa0/1 port on a switch (the port connected to the router’s Gi0/0 interface) as the trunk port. But first, here is the configuration of the switch: SW1(config)#int fa0/3 Each host is in a different VLAN, so we need to divide the physical router’s interface Gi0/0 into logical interfaces, one for each VLAN. We have a network of three hosts, a switch and a router. We will use the following network in our example: (config-subif)# ip address IP_ADDRESS SUBNET_MASK – sets the IP address for the subinterface.(config-subif)# encapsulation dot1q VLAN_ID – sets the subinterface to trunk and associates it with a specific VLAN.(config)# interface TYPE NUMBER.SUBINTERFACE – creates the subinterface and enters the subinterface command mode.To configure trunking on a router, the following commands are used: For example, the command i nterface Gi0/0.1 creates a subinterface. The subinterface number begins with the period and it is usually the same as the VLAN the subinterface will be in. The physical interface is divided into logical interfaces (known as subinterfaces), one for each VLAN.Ī subinterface is created with the interface TYPE NUMBER.SUBINTERFACE command. This method of interVLAN communication is called router on a stick (ROAS) and enables all VLANs to communicate through a single physical interface. To allow interVLAN communication, you can divide a single physical interface on a router into logical interfaces that will be configured as trunk interfaces.
Advantages of router on a stick free#
If you are studying for the exam feel free to skip this article. This topic is not included in the latest version of the CCNA exam (200-301).