VXLAN stands for Virtual Extensible Local Area Network, An encapsulation protocol which provides connectivity using tunneling at data center on Layer 2 connections over an underlying Layer 3 network. VXLAN is a tunneling protocol that tunnels Ethernet layer 2 traffic over an IP layer 3 network.

In major data centers, VXLAN (Virtual Extensible Local Area Network) is the most commonly used protocol to create overlay networks that sits on the top of the physical network layer, enabling the use of virtual networks. The VXLAN (Virtual Extensible Local Area Network ) protocol supports the virtualization of the data center network while addressing the needs of multi tenant data centers by providing the necessary segmentation on a large scale.

VXLAN (Virtual Extensible LAN) is a network virtualization technology that helps to resolve the scalability problems associated with large cloud computing deployments environment. It utilized type of encapsulation VLAN technique to encapsulate OSI layer 2 Ethernet frames within layer 4 UDP datagrams. 4789 is the default IANA-assigned destination UDP port number.

The VXLAN was mainly developed by VMware, Arista Networks and Cisco. There are some other backers of the VXLAN technology like Huawei, Broadcom, Citrix, Pica8, Big Switch Networks, Cumulus Networks, Dell EMC, Ericsson, Mellanox, FreeBSD, OpenBSD, Red Hat, and Juniper Networks etc.

VXLAN endpoints, terminate VXLAN tunnels and may be either virtual or physical switch ports, are known as VXLAN tunnel endpoints (VTEPs) VXLAN is an evolution of efforts to standardize on an overlay encapsulation protocol.

Difference between VXLAN and VLAN

Compared to VLAN which provides limited number of layer-2 VLANs uses 12-bit VLAN ID, VXLAN increases scalability up to 16 million logical networks with 24-bit VNID and allows for layer-2 adjacency across IP networks. Multicast or unicast with head-end replication (HER) is used to flood Broadcast, unknown-unicast and multicast traffic.

How VXLAN Helps in Data Centers

Data centers rapidly increased their server virtualization during the past decade, which required dramatic increases in agility and flexibility. Virtualization of the network and decoupling the virtual network from the physical network makes it easier to manage, automate services.

VXLAN is a technology which allows you to segment your networks as VLANs but also solves the scaling limitation of VLANs and provides us benefits that VLANs can not provide. one of the most important benefits of having VXLANs.

There are few more useful facilities available with VXLAN that we can theoretically create as many as 16 million VXLANs in an administrative domain, opposed to 4094 VLANs.
VXLANs provide network segmentation at the scale required by cloud builders to support very large numbers of tenants.

With traditional Layer 2 networks you are constrained by Layer 2 boundaries and forced to create large or geographically stretched Layer 2 domains. VXLAN’s functionality allows us to dynamically allocate resources within or between many other data centers and enables migration of virtual machines between servers that exist in separate Layer 2 domains by tunneling the traffic over Layer 3 networks.