Two types of network virtualization are: device pooling with the Virtual Switching System (VSS) technology, and Layer 3 network segmentation using Virtual Route Forwarding (VRF)-Lite, Cisco Easy Virtual Network (EVN), and Multiprotocol Label Switching (MPLS).
--Simplifies Layer 3 network virtualization without requiring MPLS end-to-end capabilities.
--Enhances shared services support, management, troubleshooting, and usability.
What Problems Do Network Virtualization Solutions Help Solve?
EVN is a Cisco innovation meant to overcome the overhead issues of the traditional VRF-Lite solution. With the VSS technology on Cisco Catalyst 6500 Series and now also on the Catalyst 4500-E and 4500-X Series Switches, campus networks can be designed in a way that eliminates the traditional drawbacks of multilayer network topologies, such as stateless network-level failovers resulting in increased application recovery times and business disruption; network complexity leading to lower operational efficiency and higher OpEx; and underutilized resources leading to lower return on investment and higher CapEx.
Easy Virtual Network
Cisco EVN technology uses the Virtual Network Trunk to significantly reduce the configuration required to implement network virtualization across the entire network infrastructure. The traditional VRF-Lite solution requires creating one interface per VRF on all switches and routers involved in the data path, a time-consuming process that can become a configuration management burden.
EVN also uses route replication technology to improve shared services support. Route replication technology makes it possible to link routes from a shared VRF to several segmented VRFs, simplify the configuration of importing and exporting routes, remove duplicate routing tables or routes, saving memory and CPU cycles.