Design Reference

Table Of Contents
Chapter 10: Layer 3 network design
This section describes Layer 3 design considerations that you need to understand to properly design an
efficient and robust network.
VRF Lite
The Virtual Services Platform 4000 supports the Virtual Router 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 Avaya Virtual Services Platform 4000 Configuration
— IP Routing, NN46251-505.
VRF Lite route redistribution
Using VRF Lite, Virtual Services Platform 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, 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
Network Design Reference for Avaya VSP 4000 February 2014 55