Cisco Easy Virtual Network At-A-Glance
Cisco Easy Virtual Network
Last Updated: June 2011
What Is the Value of EVN?
Easy Virtual Network (EVN) is an IP-based network virtualization solution that helps
enable network administrators to provide traffic separation and path isolation on a
shared network infrastructure. EVN uses existing Virtual Route Forwarding (VRF)-Lite
technology to:
• Simplify Layer 3 network virtualization
• Improve shared services support
• EVN improves shared services support with route replication. Multiple EVN users
may require common sets of services such as Internet connectivity, email, video,
Dynamic Host Configuration Protocol (DHCP), or Domain Name System (DNS).
Traditionally, sharing common services can be achieved through importing and
exporting routes between virtual networks using Border Gateway Protocol (BGP),
which is complex. EVN’s route replication feature allows each virtual network to
have direct access to the Routing Information Base (RIB) in each VRF, allowing the
ability to:
• Enhance management, troubleshooting, and usability
-- Link routes from a Shared VRF to several segmented VRFs but still maintain
separation where it is required
What Problems Does It Help Solve?
-- Remove dependency on the BGP route target and route distinguisher, simplifying
both configuration and complexity of importing and exporting routes
• EVN reduces network virtualization configuration significantly across the entire
network infrastructure with the Virtual Network Trunk. The traditional VRF-Lite
solution requires creating one subinterface per VRF on all switches and routers
involved in the data path, creating a lot of burden in configuration management.
-- Remove duplicate routing tables or routes, saving memory and CPU, as illustrated
in Figure 2
Figure 2. Route Replication
EVN removes the need of per VRF subinterface by using “vnet trunk” command. This
helps reduce the amount provisioning across the network infrastructure as shown in
figure 1.
R1
12.0.0.0/8
Gig0/0/2
Figure 1. VNET Trunk
Gig0/0/1
10.0.0.0/8
Edges Interfaces
Trunk Interface
802.1q
vnet tag
R1
Gig0/0/3
11.0.0.0/8
Edges Interfaces
VRF G (OSPF 3)
11.0.0.0/8 Gig0/0/3
RIB–VRF Y
+10.0.0.0/8 Gig0/0/1.Y
+11.0.0.0/8 Gig0/0/3.G
+12.0.0.0/8 Gig0/0/2.B
VRF B (OSPF 2)
12.0.0.0/8 Gig0/0/2
RIB–VRF G
+10.0.0.0/8 Gig0/0/1.Y
+11.0.0.0/8 Gig0/0/3.G
VRF Y (OSPF 1)
10.0.0.0/8 Gig0/0/1
RIB–VRF B
+10.0.0.0/8 Gig0/0/1.Y
+12.0.0.0/8 Gig0/0/2.B
802.1q
R2
•
© 2011 Cisco Systems, Inc. and/or its affiliates. Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco’s trademarks can be found at www.cisco.com/go/trademarks. Third-party
trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1007R)
Cisco Easy Virtual Network At-A-Glance
• EVN enhances network virtualization troubleshooting by making VRF-Lite easier
to deploy, operate, and scale. A routing context command mode allows network
operators to perform troubleshooting issues that pertain specifically within a VRF
without specifying the VRF name in every command. For example, after entering a
routing context, operators can perform these actions:
Router# routing-context vrf red
Router%red#
Router%red# show ip route
Router%red# ping 10.1.1.1
Router%red# telnet 10.1.1.1 Router%red# traceroute 10.1.1.1
#
#
#
#
routing table output for VRF red
Ping result using VRF red
Telnet to 10.1.1.1 in VRF red
Traceroute output in VRF red
EVN Feature Summary
• Pure IP alternative to Multiprotocol Label Switching (MPLS)
Why Cisco?
• Cisco provides the only comprehensive, single-vendor, architectural-based network
virtualization solution available today.
• Cisco is the leader in LAN switching, routing, and network virtualization.
• Cisco provides award-winning technical support to help organizations implement
sustainable business practices.
• Cisco and its partners can help customers deploy a robust, dependable solution by
taking a lifecycle approach that addresses all aspects of deployment, operations,
and optimization.
For More Information
For more information, please visit:
http://www.cisco.com/go/evn.
• Supports up to 32 virtual networks
• Backward compatible with VRF-Lite
• Supports Open Shortest Path First (OSPF) and Enhanced Interior Gateway Routing
Protocol EIGRP as the Interior Gateway Protocol (IGP)
• Can be deployed with traditional MPLS VPNs or MPLS VPNomGRE
• Supports shared services using route replication
• Full integration with Nonstop Forwarding (NSF)/Stateful Switch Over (SSO),
In-Service Software Upgrade (ISSU), and Virtual Switching System (VSS)
• Supports routing context, traceroute, debug condition, Cisco-VRF-MIB, and
VRF-aware Simple Network Management Protocol (SNMP)
© 2011 Cisco Systems, Inc. and/or its affiliates. Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco’s trademarks can be found at www.cisco.com/go/trademarks. Third-party
trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1007R)
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