Inter-Site Igp Routing Design; Layer 3 Vpn Design - Avaya 8800 Planning And Engineering, Network Design

MPLS IP VPN and IP VPN Lite

Inter-site IGP routing design

As shown in the following figure, Layer 3 IGP connectivity between all five sites is provided using
two routed VLANs where an OSPF backbone area is enabled on all five Avaya Ethernet Routing
Switch 8800/8600s. This routing instance constitutes the default routing instance of the Avaya
Ethernet Routing Switch 8800/8600 platform which is know as the Global Routing Table (GRT) or
VRF0. The purpose of this routed GRT routing instance is purely to provide IP connectivity between
a number of Circuitless IP (CLIP) interfaces that must created on each Ethernet Routing Switch
8800/8600.
Figure 125: GRT IGP VLAN running OSPF and full mesh of IBGP peerings
Each Avaya Ethernet Routing Switch 8800/8600 is configured with a Circuitless IP address (CLIP)
host address using a 32-bit mask. From these CLIP interfaces, a full mesh of IBGP peerings is
configured between the Ethernet Routing Switch 8800/8600s in each site. The IBGP peerings are
enabled for VPNv4 and IP VPN Lite capability and are used to populate the IP routing tables within
the VRF instances used to terminate the Layer 3 VPNs.
To support a larger number of sites, Avaya recommends the use of BGP Route-Reflectors. This can
be accomplished by making the Ethernet Routing Switch 8800/8600 at site 1 and site 2 redundant
Route-Reflectors and every other site a Route-Reflector client.

Layer 3 VPN design

The Layer 3 VPNs are implemented using Avaya IP VPN Lite.
June 2016 Planning and Engineering — Network Design
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