Connectivity Guide

VXLAN

A virtual extensible LAN (VXLAN) extends Layer 2 (L2) server connectivity over an underlying Layer 3 (L3) 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 L2 overlay mechanism on an existing L3 network by encapsulating the L2 frames in L3 packets. The VXLAN-shared

forwarding domain allows hosts such as virtual and physical machines, in tenant L2 segments to communicate over the shared IP network.

Each tenant L2 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 8. 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.

VXLAN 679