What is the purpose of VXLAN (Virtual Extensible LAN)?

VXLAN, which stands for Virtual Extensible LAN, is a network virtualization technology that addresses the scalability and isolation challenges in large data center environments. It is primarily designed to overcome the limitations of traditional VLANs (Virtual Local Area Networks) by providing a more scalable and flexible solution for creating virtual networks in a virtualized infrastructure.

Here are the key purposes and features of VXLAN:

  1. Scalability:
    • VXLAN allows the creation of a large number of logical network segments (16 million virtual segments) compared to the limited number available in traditional VLANs (4096).
    • This scalability is essential in modern data centers where there is a need to support a large number of virtual machines (VMs) and applications.
  2. Isolation:
    • VXLAN provides network isolation by segmenting the physical network into multiple virtual networks, known as VXLAN segments or VXLAN networks.
    • This isolation enables multiple tenants or applications to share the same physical infrastructure without interfering with each other.
  3. Overcoming VLAN Limitations:
    • Traditional VLANs have limitations in terms of scalability and flexibility. VXLAN extends the VLAN concept by using a 24-bit VNID (VXLAN Network Identifier), allowing for a much larger number of unique identifiers.
    • VXLAN also allows for the creation of Layer 2 overlay networks over Layer 3 infrastructure, overcoming the constraints of VLANs that are limited to Layer 2.
  4. Layer 2 over Layer 3:
    • VXLAN encapsulates Layer 2 Ethernet frames within Layer 3 UDP (User Datagram Protocol) packets. This allows the virtualized network to be extended over an IP-based infrastructure, making it more adaptable to modern data center architectures.
  5. Flexibility and Mobility:
    • VXLAN facilitates workload mobility and flexibility by decoupling virtual machine placement from the underlying physical network. VMs can be moved across different physical hosts and even across data centers while maintaining their network connectivity.
  6. Multi-Tenancy Support:
    • VXLAN is well-suited for multi-tenant environments where different customers or business units share the same physical infrastructure. Each tenant can have its own isolated VXLAN segment, ensuring privacy and security.
  7. Cloud and Virtualization:
    • VXLAN is particularly beneficial in cloud environments and virtualized data centers. It allows for the creation of virtual networks that span across different hypervisors, data centers, and cloud providers.
  8. Interoperability:
    • VXLAN is designed to work seamlessly with existing networking protocols and devices. It operates at the data plane level, making it compatible with various network hardware and software solutions.