In data centers, VXLAN is the most commonly used protocol to create overlay networks that sit on top of the physical network, enabling the use of a virtual network of switches, routers, firewalls, load balancers, and so on. The VXLAN protocol supports the virtualization of the data center network and addresses the needs of multi-tenant data centers by providing the necessary segmentation on a large scale.

Problems VXLAN Addresses in Virtualized Data Center Networks

Data centers have rapidly increased their server virtualization over the past decade, resulting in 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, and orchestrate.

What Can You Do with VXLAN in Virtualized Data Center Networks?

Creating a virtual overlay network benefits the physical, or underlay network, which can be a simple IP network that is concerned with delivering packets to destinations. An overlay network adds simplicity, resiliency, and scale to the physical network.

How Does VXLAN Work in Virtualized Data Center Networks?

VXLAN is a tunneling protocol that encapsulates Layer 2 Ethernet frames in Layer 3 UDP packets, enabling you to create virtualized Layer 2 subnets, or segments, that span physical Layer 3 networks. Each Layer 2 subnet is uniquely identified by a VXLAN network identifier (VNI) that segments traffic. The entity that performs the encapsulation and decapsulation of packets is called a VXLAN tunnel endpoint (VTEP) and resides in hypervisor hosts.

In the following figure, when VTEP1 receives an Ethernet frame from Virtual Machine 1 (VM1) addressed to Virtual Machine 3 (VM3), it uses the VNI and the destination MAC to look up in its forwarding table for the VTEP to send the packet to. VTEP1 adds a VXLAN header that contains the VNI to the Ethernet frame, encapsulates the frame in a Layer 3 UDP packet, and routes the packet to VTEP2 over the Layer 3 network. VTEP2 decapsulates the original Ethernet frame and forwards it to VM3. VM1 and VM3 are completely unaware of the VXLAN tunnel and the Layer 3 network between them.

Juniper Networks Implementation

Juniper Networks MX Series routers, QFX5100 switches, and EX9200 switches can act as VTEP gateways, encapsulating/decapsulating VXLAN packets. The MX Series routers and EX9200 switches can also route between different VXLANs.

Cloud Analytics Engine is an integrated analytics solution that provides visibility into devices within a network’s physical and virtual layers for data collection, analysis and correlation. It is an open solution that supports RESTful APIs for third-party integration.

Junos Space Network Director is a network management solution that visualizes, analyzes, and controls the entire enterprise network from the data center to the campus, physical to virtual, and wired to wireless, through single management screen.