Router-on-a-Stick Inter-VLAN Routing

When VLAN-tagged traffic enters the router interface, it is forwarded to the VLAN subinterface. After a routing decision is made based on the destination IP network address, the router determines the exit interface for the traffic. If the exit interface is configured as an 802.1q subinterface, the data frames are VLAN-tagged with the new VLAN and sent back out the physical interface

Since this supports up to 50 VLANs, we will focus on this method for most of our VLAN discussion

Router on a Stick (Trunk) only requires one physical Ethernet interface to route traffic between multiple VLANs on a network

The Router interface is configured as an 802.1q trunk and connected to a trunk port on the switch using subinterfaces to identify routable VLANs

Each subinterface is independently configured with an IP address and VLAN assignment

Trunk

The Stick

Uses 802.1q Tag