Deployment Guide

17 VCF on VxRail Multirack Deployment using BGP EVPN
4.1.1 BGP ASNs and router IDs
Figure 12 shows the autonomous system numbers (ASNs) and router IDs used for the leaf and spine
switches in this guide. Spine switches share a common ASN, and each pair of leaf switches shares a
common ASN.
ASNs should follow a logical pattern for ease of administration and allow for growth as switches are added.
Using private ASNs in the data center is the best practice. Private, 2-byte ASNs range from 64512 through
65534.
In this example, 65100 is used on both switches at the spine layer. Leaf switches use the next available
ASNs, 65101, for example, and the last digit is used to identify the leaf pair. Extra spine switches would be
assigned the existing ASN for the spine layer, 65100. Extra leaf switches would be added in pairs with the
next pair assigned an ASN of 65103.
The IP addresses shown are loopback addresses that are used as BGP router IDs. Loopback addresses
should follow a logical pattern to make it easier to manage and allow for growth. In this example, the
10.0.0.0/16 IP address space is used. The third octet in the address represents the layer, “1” for the spine
layer and “2” for the leaf layer, and the fourth octet is the counter for the appropriate layer
AS65102AS65101
10.0.2.4
10.0.2.3
VLTi
10.0.2.2
10.0.2.1
VLTi
Spine 1 Spine 210.0.1.1 10.0.1.2
AS 65100
BGP ASNs and router IDs
4.1.2 Point-to-point IP networks
Establishing a logical, scalable IP address scheme is important before deploying a leaf-spine topology. The
point-to-point links used in this deployment are labeled A-H in Figure 13.
Rack 2Rack 1
Leaf 2b
Leaf 2a
VLTi
Leaf 1b
Leaf 1a
VLTi
Spine 1 Spine 2Spine 1 Spine 2
BA FEDC G H
Point-to-point networks