SW1(config-if)# spanning-tree portfast trunk SW1(config-if)# switchport trunk encapsulation dot1q SW1(config-if)# description Trunk-to-Router SW1(config)# interface gigabitethernet 0/1 Since all Cisco swiches contain VLAN1 (Default VLAN), we only need to create VLAN2: STEP 1 - Switch Configurationįirst step is to create the required two VLANs on our Cisco switch and configure them with an IP address. This diagram shows an illustration of the above configuration. This example will show you how to configure a Cisco router and switch in order to create a trunk link between them and have the router route packets between your VLANs. If you would like to read more on VLAN routing and VLAN theory, you can visit our popular VLAN Section that covers all related topics and terms found in this article. Packets running between VLANs are routed via the CCME router connected to the switch using one physical port configured as a trunk port on both ends (switch and router).

This configuration ensures availability and stability of the VoIP service, especially during peak traffic hours in your network. Because VoIP implementations require you to separate the data and voice network in order to route packets between them, you need either a layer 3 switch or a router. Our example is based on a scenario you are most likely to come across when dealing with VoIP networks. A good example of a router-on-a-stick configuration (which also happens to be the one we are going to cover) would be a Call Manager Express installation where there is the need to split the VoIP network, consisting of your Cisco IP Phone devices, from your data network where all workstations and servers are located.

While some believe the term 'router-on-a-stick' sounds a bit silly, it's a very popular term and commonly used in networks where no layer-3 switch exists. In this setup, the switch is configured with multiple VLANs and the router performs all routing between the different networks/VLANs. Router-on-a-stick is a term frequently used to describe a setup up that consists of a router and switch connected using one Ethernet link configured as an 802.1q trunk link.

Basic router configuration