Cisco Catalyst 4500 Series, Software Configuration Manual

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Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 83 Configuring Easy Virtual Network
About Easy Virtual Network
•
OSPFv3 is not supported; OSPFv2 is supported.
• The following features are not supported by EVN:
–
IS-IS
– RIP
–
Route replication is not supported with BGP
– Certain SNMP set operations
•
The following are not supported on an EVN trunk:
– Access control lists (ACLs)
–
BGP interface commands are not inherited
– IPv6, except on vnet global
–
Network address translation (NAT)
– NetFlow
–
Web Cache Communication Protocol (WCCP)
About Easy Virtual Network
Easy Virtual Network (EVN) builds on the existing IP-based virtualization mechanism known as
VRF-Lite. EVN provides enhancements in path isolation, simplified configuration and management, and
improved shared service support. EVN is backward compatible with VRF-Lite to enable seamless
network migration from VRF-Lite to EVN.
EVN supports IPv4, static routes, Open Shortest Path First version 2 (OSPFv2), and Protocol
Independent Multicast (PIM) and Multicast Source Discovery Protocol (MSDP) for IPv4 Multicast
routing. EVN also supports Cisco Express Forwarding (CEF) and Simple Network Management
Protocol (SNMP).
Virtual Network Tags Provide Path Isolation
It is not uncommon to have different user groups running on the same IP infrastructure. Various business
reasons require traffic isolation between different groups. The figure below shows two user groups, Red
and Green, running on the same network. Prior to network virtualization, there is no separation of traffic
between the two groups. Users in the Red user group can access the server in the Green user group, and
vice versa.
Without network virtualization, path isolation can be achieved by using access control, which is
expensive to maintain, prone to error and does not support unique routing and forwarding tables per
network