Post on 20-Jan-2017
transcript
Topic: Virtual eXtensible LAN(VXLAN)By Math Tea – eintellegoNetworks
math@eintellegonetworks.asia
Date: 30 March, 2016
Contentsq VXLAN Introduction
q VXLAN Benefits
q Reference
What is VXLAN?q Virtual eXtensible Local Area Network
q Stretches Layer 2 connections over a Layer 3 network by encapsulating Ethernet frames in a VXLAN packet that includes IP addresses
Layer 3 Network
Layer 2 over Layer 3Layer 2 Layer 2
VTEP-A VTEP-BHost 1 Host 2
VNI 6000
q Theoretically create as many as 16 million VXLANs in an administrative domain
q Enable migration of virtual machines between servers in separate Layer 2 domains by tunneling over Layer 3 networks
q No need to use STP to converge the topologyu All links can be used u Traffic can be load balancedu Maximizes performance
Benefits of using VXLANs
VXLAN Network Identifier(VNI)
q The VNI was designed to address the growing needs of multi-tenant data centers.
q VNI is 24 bit length which is more than 16 million VXLAN segments(224 =16,777,216)
Virtual Tunnel Endpoint(VTEP)q Devices that support VXLANs are called virtual tunnel
endpoints (VTEPs). They can be end hosts or network switches or routers.
q VTEPs encapsulate VXLAN traffic and decapsulate that traffic when it leaves the VXLAN tunnel.
q VTEPs add a number of fields, including the following:
u Outer MAC destination address (MAC address of the tunnel endpoint
VTEP)
u Outer MAC source address (MAC address of the tunnel source VTEP)
u Outer IP destination address (IP address of the tunnel endpoint VTEP)
u Outer IP source address (IP address of the tunnel source VTEP)
u Outer UDP header
u A VXLAN header that includes a 24-bit field
Virtual Tunnel Endpoint(VTEP)
VXLAN Packet format
• LSRs forward packets based on label and swap labels:
- The last LSR in the path also removes the label and forward the IP packets as normal IP Routing
Underlay Network
VXLAN Encapsulation
VNI =100
VNI =200
VNI =100
VNI =200
Overlay Network
Reference
• https://tools.ietf.org/html/rfc7348
• http://www.juniper.net/documentation/en_US/junos14.1/topics/topic-map/vxlan-qfx-series.html
• https://www.youtube.com/watchv=Jqm_4TMmQz8