Design Reference

Chapter 13: Layer 3 network design
This chapter describes Layer 3 design considerations that you need to understand to properly
design an efficient and robust network.
VRF Lite
The Avaya Virtual Services Platform 4000 Series supports the Virtual Routing and Forwarding
(VRF) Lite feature, which supports many virtual routers, each with its own routing domain. VRF Lite
virtualizes the routing tables to form independent routing domains, which eliminates the need for
multiple physical routers.
To use VRF Lite, you must use the Premier Software License.
For more information about VRF Lite, see Configuration - IP Routing for Avaya Virtual Services
Platform 4000 Series, NN46251-505.
VRF Lite route redistribution
Using VRF Lite, VSP 4000 can function as many routers; each VRF routing engine works
independently. Normally, no route leak occurs between different VRFs. Use the route redistribution
option to facilitate the redistribution of routes. VRFs can redistribute Open Shortest Path First
(OSPF), Routing Information Protocol (RIP), Border Gateway Protocol (BGP), direct routes, and
static routes.
If you enable route redistribution between two VRFs, ensure that the IP addresses do not overlap.
The software does not enforce this requirement.
VRF Lite capability and functionality
On a VRF instance, VRF Lite supports the following protocols: IP, Internet Control Message
Protocol (ICMP), Address Resolution Protocol (ARP), static routes, default routes, RIP, OSPF,
external BGP (eBGP), route policies, Virtual Router Redundancy Protocol (VRRP), and the Dynamic
Host Configuration Protocol/BootStrap Protocol relay agent.
The device uses VRF Lite to perform the following actions:
• Partition traffic and data, and represent an independent router in the network
• Provide virtual routers that are transparent to end users
• Support overlapping IP address spaces in separate VRFs
• Support addresses that are not restricted to the assigned address space given by host Internet
Service Providers (ISP)
• Support eBGP
June 2015 Network Design Reference for Avaya VSP 4000 Series 75
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