Skip to main content

Ccie exam fee A brief look at vxlan technology (4)

Ccie exam fee A brief look at vxlan technology (4)

VXLAN tunnel  


"Tunnel" is a logical concept, it is not new, such as the familiar GRE. To put it bluntly, the original message is "transformed" and "packaged" so that it can be transmitted on a bearer network (such as an IP network). From the perspective of the host, it is as if there is a straight link between the start and end of the original message. Ccie exam fee.And this seemingly straight link is the "tunnel." As the name implies, the "VXLAN tunnel" is used to transmit packets that are encapsulated in VXLAN. It is a virtual channel established between two VTEPs.

The payload message inside VXLAN specified in RFC7348 must be an Ethernet packet, which limits the scope of use of the VXLAN protocol. In order to allow VXLAN to support Overlay transmission of other protocol messages more widely, the RFC draft is exploring VXLAN Generic Protocol Encapsulation (GPE), which is a VXLAN general protocol encapsulation.



The GPE package uses some of the reserved bits specified in the original FRC7348.

• Version (Ver): Indicates the VXLAN GPE protocol version. The initial value is 0.

• Next Protocol Bit (P bit): If the P bit is 1, the Next Protocol field is valid.

• BUM Traffic Bit (B bit): If the B bit is 1, it indicates that the encapsulated packet in the VXLAN is a BUM packet.Ccie exam fee.

• OAM Flag Bit (O bit): If the O bit is 1, the encapsulated packet in the VXLAN is an OAM packet.

• Next Protocol: 8 digits. Indicates the protocol format of the encapsulated packets inside the VXLAN.



BUM (Broadcast, Unknown-unicast, Multicast) is broadcast, unknown unicast, and multicast traffic. According to different ways of copying flood traffic, it can be divided into unicast routing mode (head-end replication) and multicast routing mode (core replication). In the head-end replication mode, the VTEP is responsible for copying the packets. The unicast mode sends the copied packets to the local site through the local interface and sends them to all remote VTEPs in the VXLAN through the VXLAN tunnel. After receiving the VXLAN packet, the remote VTEP decapsulates the packet and floods the original data in the VXLAN of the local site. To avoid loops, after the remote VTEP receives a packet from the VXLAN tunnel, it will not flood it to other VXLAN tunnels.


VXLAN Layer 3 Gateway - L3 Gateway


The VXLAN Layer 3 gateway provides the Layer 3 forwarding function of the VXLAN. The VXLAN is associated with the VSI virtual interface (VXLAN virtual interface). The VSI virtual interface is assigned the IP address as the gateway of all VMs in the VXLAN.

The main functions of the VXLAN Layer 3 Gateway:

• Realize mutual visits between virtual machines and non-VXLAN networks in VXLAN

• Completing virtual machine exchanges across VXLAN

VXLAN Layer 3 gateways are available in both centralized and distributed modes depending on how they are deployed.



Centralized gateways, which are all centered on the Spine device. All traffic across VXLAN, VXLAN and non-VXLAN access traffic need to pass Spine. The advantage of centralized gateway is that all the flows can pass through Spine device, which makes it easier to implement flow control and automatic draining. The disadvantage is that the Spine device is under pressure and is not conducive to large-scale deployment.Ccie exam fee



In the distributed VXLAN Layer 3 gateway solution, each VTEP device can act as a VXLAN IP gateway to perform Layer 3 forwarding of traffic at the local site. Distributed layer 3 gateway can be a good solution to the problem that leads to excessive pressure in Spine device due to the concentration of traffic. Ccie exam fee.It can also be flexibly extended on the group network. On a distributed gateway network, the Spine device is not a VTEP. It is only part of the Underlay network and is responsible for forwarding ordinary IP packets.



VXLAN has become the best choice for the current SDN Overlay technology due to its simple data plane and good compatibility, but VXLAN still has a long way to go in the future.

For example, exploring the VXLAN GPE package is a direction, and solving the QoS of the VXLAN tunnel is also a direction. The control plane needs to do more, how to better implement on-demand customization, how to achieve intelligent traffic adjustment, how to better compatible with heterogeneous devices, and so on. Ccie exam fee.I believe that the future will give us a better answer.


Part of the content is selected from: H3C product support and service technology column "Interpretation of VXLAN"


Publisher:IE LAB

publish Website: http://ielab.network

WhatsApp: +8617782638871

Skype:live:ielab.anna


Ccie exam fee A brief look at vxlan technology

Comments

Post a Comment

Popular posts from this blog

Cisco ccie exam Linux overview and history

      Cisco ccie exam Linux overview and history Simply put, the Linux operating system is a clone of the UNIX operating system, which was born on October 5, 1991 (the first time it was officially announced). It's the same as Microsoft's Windows, apple's MAC OS and android on mobile phones. Cisco ccie exam.Compared to ordinary people, Linux system may be relatively unfamiliar, and most of them are probably familiar with Windows system. Since the graphical interface of Windows is simpler and easier to use, Windows occupies more markets, and Linux systems are mainly command-line operations, which are more demanding for professionalism.Cisco ccie exam Linux systems are stable, secure, and have strong concurrency, so they are widely used in the server field. The professional servers are almost all Linux systems. Linux is open source, free, everyone can see the source code of Linux, you can use Linux for free. And the Linux kernel is short and lean, and some can only be a ...
Post a Comment
Read more

Cisco ccie exam Introduction to the OpenFlow protocol

Cisco ccie exam Introduction to the OpenFlow protocol OpenFlow, a network communication protocol, belongs to the data link layer and can control the forwarding plane of the network switch or router, thereby changing the network path of the network packet. OpenFlow protocol background: Forwarding and control separation is one of the essential features of SDN networks.In the SDN network architecture, the control plane is separated from the forwarding plane, the management and state of the network are logically grouped together, and the underlying network infrastructure is independent from the application, thereby enabling the network to achieve unprecedented programmable, controllable, and automated capabilities.Cisco ccie exam. This makes it easy for users to build highly scalable elastic networks based on business needs. To implement the transfer separation architecture of the SDN network, a communication interface standard needs to be established between the SDN controller and the dat...
Post a Comment
Read more

CISCO CCIE EXAM 5G and WIFI6, still can't tell? (1)

cisco ccie exam 5G and WIFI6, still can't tell? (1) Ⅰ. the opening: On October 3, 2018, the Wi-Fi Alliance officially incorporated WiFi based on the 802.11ax standard into the regular army and became the sixth generation WiFi technology. The WiFi specification was renamed, the standard 802.11n was renamed to WiFi 4, the standard 802.11ac was renamed to WiFi 5, and the new standard 802.11ax was renamed to WiFi 6. (Of course, the previous generation of 802.11b/a/g can be chased as WiFi 1/2/3) Not only changed the naming convention of WiFi, but also in the network connection of WiFi devices. Also all use the new UI icon. The icon will display the level of the WiFi network you are currently connected to through the most intuitive numbers. Wi-Fi is well known to us. Wi-fi has evolved from 802.11b in 1999 and has gone through five generations. The Wi-Fi Alliance announced the simplification of the name of the new Wi-fi to Wi-fi6 when it introduced the new generation of 802.11ax stan...
Post a Comment
Read more