Easy Virtual networking is a technology that allows for the creation of separate networks with separate routing tables and routing instances using the same physical topology. The IP addressing for the networks can even overlap with no problem. The networks are kept separate using the network ID tags in a similar fashion to the way switches keep VLANs separate by using VLAN tags.
The interface must be able to support 802.1q encapsulation. The EVN trunk carries the traffic of multiple virtual routing and forwarding (VRF) instances, with the traffic of each instance tagged with an ID called the virtual network tag. Since the VLAN ID field of an 802.1q encapsulated packet is used for this ID, the link must be one that supports 802.1q.
An EVN trunk interface cannot also be configured for VRF-Lite.
multiple virtual routing and forwarding (VRF) instances are carried by an EVN trunk
VRF-Lite is an earlier technology that accomplishes the same goal, but lacks the simplicity of EVN.
Neither RIP nor OSPFv3 is supported in Easy Virtual Networking EVN at all.
VRF-Lite an earlier VPN technology is that accomplishes the same goal as Easy VPN but lacks the simplicity of EVN
When a virtual routing and forwarding (VRF) instance is defined, it will have a name and a tag number. The tag number is used by the router to dynamically create a subinterface on the specified physical interface of the EVN trunk. The tag number is appended to the physical interface ID. Since the virtual network (vnet) trunk was defined as FastEthernet1/0/0, the subinterface for vrf red will be FastEthernet1/0/0.3. All subinterfaces on the trunk will use the same IP address as the physical interface defined as the trunk.
Easy virtual networking (EVN) is a technology that allows for multiple logical networks to use the same physical infrastructure. EVN trunks carry the traffic of multiple VRFs. While the subinterfaces dedicated to each VRF use the same IP address (that of the physical interface of the EVN trunk), no IP address conflicts ever occur because each VRF maintains its own routing and forwarding tables, and while on the trunk, each uses a VRF tag to separate the traffic from each VRF.