API 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 identified by a 24-bit ID called a VXLAN network identifier (VNI).

Deployed as a VXLAN gateway, an OS10 switch performs encapsulation/de-encapsulation of L2 frames in L3 packets while

tunneling server traffic. 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 11. 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.

Virtual extensible

LAN (VXLAN)

A type of network virtualization overlay that encapsulates a tenant payload into IP UDP packets for

transport across the IP underlay network.

VXLAN network

identifier (VNI)

A 24-bit ID number that identifies a tenant segment and transmits in a VXLAN-encapsulated packet.

VXLAN tunnel

endpoint (VTEP)

A switch with connected end hosts that are assigned to virtual networks. The virtual networks map to

VXLAN segments. Local and remote VTEPs perform encapsulation and de-capsulation of VXLAN headers

for the traffic between end hosts. A VTEP is also known as a network virtualization edge (NVE) node.

880 VXLAN