A Virtual Extendable Local Area Network (also known as VXLAN) is a network virtualization technology that allows multiple organizations to use a single network without compromising security. With the rise of cloud technology, these data centers play a critical role in running critical applications and businesses around the world.

Because VXLAN plays a critical role in modern network architectures, understanding VXLAN is critical for IT professionals and network administrators.

What is VXLAN and how does it work?

A VXLAN is a tunneling protocol that is established between a source network device and a destination network device. It works by fragmenting Layer 2 Ethernet frames and encapsulating them in UDP packets (User Datagram Protocol).

This helps to meet the limitations of VLANs on virtual networks in cloud virtualization technology and provides a unique and scalable solution to the problem. VXLAN facilitates workload mobility and seamless migration by providing an abstraction layer that separates the virtual network from the physical infrastructure.

In simple terms, VXLAN allows multiple applications or organizations to use a single network. Organizations and businesses are like tenants in a network.

Just as tenants belong to the same building and each apartment is a separate entity, VXLAN is a discrete private network segment within a shared network. Tenants can't see traffic from other tenants or organizations, improving network efficiency and enhancing security.

How Does VXLAN Work?

VXLAN operates within the Layer 2 data link layer, allowing the layer to be segmented and each virtual segment network assigned a specific number called VNI (VXLAN Network Identifier). By encapsulating Ethernet frames into UDP packets (User Datagram Protocol), the allocation of VNI helps to isolate network traffic within Layer 2. This enables traffic to be transmitted over the IP network in the form of Layer 3 network infrastructure.

What is a VXLAN diagram?

Virtual Extensible LANs also create overlay networks, allowing the creation of VXLAN networks that are independent of any underlying physical network. Network overlay plays a critical role in modern networks, enabling VXLAN to create virtual networks on top of existing physical infrastructure.

What is VTEP?

A VTEP is a VXLAN tunnel endpoint that is used to encapsulate and decapsulate VXLAN network packets. They can be physical switches or virtual. By encapsulating and decapsulating VXLAN segments, VTEP ensures communication between virtual machines or devices in different VXLAN segments.

VLAN vs. VXLAN

VLANs help create a virtual network within a LAN and group together devices that frequently communicate with each other. VXLAN is a network virtualization technology designed to overcome the limitations of VLANs by allowing organizations to use a single network.

VLANs operate at Layer 2, dividing the physical network into multiple broadcast domains, while VXLANs operate at Layer 2 on top of Layer 3. In Layer 2, it encapsulates Ethernet frames into UDP packets.

VLANs use 12-bit identifiers and allow 4094 networks on Ethernet, while VXLANs use 24-bit identifiers and can create up to 16 million networks. VLANs use the spanning tree protocol and block half of the ports, while VXLANs allow all ports to be used, increasing efficiency. VXLANs are designed to be compatible with existing infrastructure and can coexist with legacy VLANs

Advantages and limitations of VXLAN

VXLAN has a number of advantages and can be very useful in many situations. Let's explore the advantages and limitations of this technology.

Advantages of VXLAN

VXLAN has a number of advantages, including:

Scalability:VXLAN is highly scalable and can accommodate up to 16 million isolated networks. This is useful for organizations and data centers, enabling them to accommodate multiple tenants.

Dynamic VM migration: VXLAN allows you to move VM hosts from one physical host to another without disrupting service or letting users know. This is important for maintaining service continuity and making efficient use of available resources.

Easy to manage and configure: Since VXLAN is a software network, it can be easily managed and configured using a centralized controller.

Privacy and security: Network segmentation enhances security and privacy so that one tenant can't see another tenant's traffic.

Encryption:VXLAN does not provide encryption by nature, but it can use encryption mechanisms.

Limitations of VXLAN

Despite the many benefits of VXLAN, there are some limitations to be aware of. These include:

Additional cost: Encapsulating Layer 2 inside UDP packets can result in increased costs.

Complexity:VXLAN can get complex, especially when dealing with multiple segments and VTEPs.

Impact on performance when working with physical network devices: Enhanced MAC addresses and VXLAN traffic affect the performance of physical switches and network devices.

How Do I Implement VXLAN?

To implement VXLAN, VTEP needs to be configured on network devices and VXLAN needs to be deployed on downstream interfaces to provide access services. Deploy VXLAN on the upstream interface, establish a VXLAN tunnel, and forward packets to the network after the deployment is complete.

In short, the implementation of VXLAN can be summarized into three steps: packet identification, VXLAN tunnel establishment, and packet forwarding.

Before implementing VXLAN, ensure that your existing physical network is properly configured to support VXLAN. Enable VXLAN on the interface and assign VNI to VXLAN to distinguish between virtual networks. After that, specify the UDP port. Then, configure the VTEPIT address, specify the remote IP, and enable VXLAN on the overlay interface.

Adjust the configuration based on the network hardware of a particular device and the settings can be verified with commands such as "showvxlantunnel" and "showvxlanpeers".

Some deployments may use a Network Virtualization Overlay Controller (NVOC) for automation and management of VXLAN configurations. Learn more about VXLAN configuration and implementation.

VXLAN deployment

The method of deploying VXLAN depends on where the VTEP is located. The following describes the three main ways to deploy VXLANs.

Host-based VXLAN

In this mode, VXLANs are deployed directly on a single host without the need to go through physical devices such as switches. It should be noted that the operating system of the host must support VXLAN and related kernel modules or drivers.

Encapsulation and decapsulation are done through a virtual switch that acts as a VTEP. Host-based VXLAN provides greater flexibility and control at the host level.

Gateway-based VXLAN

The deployment of gateway-based VXLANs is done directly on network gateway devices, such as routers and Layer 3 switches. Encapsulation and decapsulation in a gateway-based VXLAN is done through a switch or router that acts as a VTEP.

These devices are called gateway VXLANs. This method is typically used to connect VXLAN-based virtual networks with non-VXLAN networks. Gateway-based VXLAN provides routing flexibility and interoperability.

Hybrid VXLAN

Hybrid VXLAN refers to a deployment that combines gateway-based VXLAN and host-based VXLAN in the same network environment. In a hybrid implementation, some VTEPs are on hardware and some are on virtual switches.

The hybrid approach combines the best of both VXLANs, providing flexibility, efficiency, and scalability.

summary

VXLAN is an indispensable technology for data centers in a digitally evolving world. It bridges the limitations of VLANs and enhances scalability, performance, security, and network virtualization through isolated segmentation in cloud environments.

Its ability to adapt to modern IT infrastructure is unmatched, which makes it an important subject for all IT professionals, especially those preparing to take the Network+ test.