Connectivity Guide

VXLAN
A virtual extensible LAN (VXLAN) extends Layer 2 server connectivity over an underlying Layer 3 transport network in a virtualized data
center. A virtualized data center consists of virtual machines (VMs) in a multi-tenant environment. OS10 supports VXLAN as described in
RFC 7348.
VXLAN provides a Layer 2 overlay mechanism on an existing Layer 3 network by encapsulating the Layer 2 frames in Layer 3 packets. The
VXLAN shared forwarding domain allows hosts (virtual and physical machines) in tenant Layer 2 segments to communicate over the shared
IP network. Each tenant Layer 2 segment is identied by a 24-bit ID called a VXLAN network identier (VNI).
Deployed as a VXLAN gateway, an OS10 switch performs encapsulation/de-encapsulation of L2 frames in L3 packets while tunneling
server trac. In this role, an OS10 switch operates as a VXLAN tunnel endpoint (VTEP). Using VXLAN tunnels, server VLAN segments
communicate through the extended L2 forwarding domain.
Figure 5. VXLAN topology
VXLAN concepts
Network
virtualization overlay
(NVO)
An overlay network extends L2 connectivity between server virtual machines (VMs) in a tenant segment over an
underlay L3 IP network. A tenant segment can be a group of hosts or servers that are spread across an underlay
network.
• The NVO overlay network uses a separate L2 bridge domain (virtual network), which is independent of legacy
VLAN forwarding.
• The NVO underlay network operates in the default VRF using the existing L3 infrastructure and routing
protocols.
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514 VXLAN