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Dell EMC VxRail Multirack Deployment Guide
1
Introduction
VxRail appliances have no backplane, therefore, communication between its nodes is facilitated using the
network switches. Communication between the nodes uses auto-discovery capabilities. New VxRail nodes
advertise themselves on the network and are discovered by the VxRail Manager.
Modern data centers commonly use a routed IP environment that is based on either the Open Shortest Path
First (OSPF) or Border Gateway Protocol (BGP) routing protocols. In these environments, each rack is a
unique IP subnet. For a successful VxRail multirack deployment, all nodes must be able to reach each other
through a single Layer 2 (L2) domain. Network Virtualization solves this problem by carving a single physical
network (underlay) into multiple virtual networks (overlays), or Network Virtualization Overlays (NVOs). The
standards-based protocol used to create NVOs is Virtual Extensible LAN (VXLAN). VXLAN based solutions
offer one of the most cost-effective and straightforward paths to enable the routed underlay to forward L2
traffic between separate subnets.
Figure 1 shows Dell EMC Networking switches in Virtual Link Trunking (VLT) pairs connected over an OSPF
enabled IP underlay using VXLAN tunnels. This topology enables the creation of multiple virtual networks
over one common IP underlay network. In this example, the five required VLANs for a successful VxRail
deployment are each encapsulated in separate VXLANs. The Internal Management VLAN is used to discover
adjacent VxRail nodes and perform initialization to create or expand a VxRail cluster. NVOs allows multirack
VxRail discovery and deployment to take place.
Rack 1
Rack 2
OSPF Area 0
Spine 1
Z9264-ON
Spine 2
Z9264-ON
VxRail Nodes
iD
R
A
C
VxRail Nodes
iD
R
A
C
NIC2
NIC1
NIC2
NIC1
Leaf 1A
S5248F-ON
VTEP
Leaf 1B
S5248F-ON
VTEP
Leaf 2A
S5248F-ON
Leaf 2B
S5248F-ON
VTEP
VTEP
VXLAN
External Management
Internal Management
vSAN
vMotion
Guest VM Networks
ID VLAN Name
Logical diagram showing VXLAN encapsulation over an IP underlay network
