Many data centers today have moved from a legacy L2 design to a modern L3 architecture. L3 designs allow simplified troubleshooting, clear upgrade strategies, multi-vendor support, small failure domains, and less vendor lock-in. However, many applications, storage appliances and tenant considerations still require L2 adjacency.
Virtual eXtensible LAN (VXLAN) is a MAC-in-UDP technology that provides layer 2 connectivity between networks across an IP network. VXLAN is typically used to extend layer 2 segments across an entire data center or between remote data centers. It is also used to provide multi-tenant services, where the same IP/MAC addresses or VLANs are used on different network segments.
Challenges with using traditional VLAN
- VXLAN networks are eliminating the need for Spanning Tree Protocol (STP) to prevent loops.
- VXLAN networks exhibit superior scalability due to their ability to operate without requiring configuration of spine switches. These switches function as route reflectors, facilitating rapid provisioning and contributing to the overall scalability of the network
- VXLAN's flexibility allows for the creation of virtual networks that transcend physical network or data center boundaries, enabling more adaptable network design and management.
- VXLAN enables seamless VM or workload migration between physical servers without necessitating network reconfiguration and minimizing business interruptions and impact on users.
VXLAN overcomes these deficiencies and allows the network operator to optimize on an L3 routed fabric. A L2 overlay can still be accomplished, but no longer requires STP for control plane convergence due to the reliance of EVPN as the control plane. EVPN exchanges MAC information through a BGP address family, instead of relying on the inefficiencies of broadcast flood and learn. Plus, VXLAN uses a 24-bit ID that can define up to 16 million virtual networks, whereas VLAN only has a 12-bit ID and is limited to 4094 virtual networks.
Benefits of VXLAN
- Supports more virtual switched domains than VLANs: Each VXLAN is uniquely identified by a 24-bit VXLAN ID, called the VXLAN Network Identifier (VNI). The total number of VXLANs can reach 16 million. This makes VXLAN a better choice than 802.1Q VLAN for isolating traffic for user terminals.
- A VXLAN segment differentiates individual logical networks so that several isolated layer 2 VXLAN networks can coexist on a common layer 3 infrastructure. (Hosts in different VXLAN segments cannot communicate with each other. Each VXLAN segment can be treated as a tenant in a data center topology.)
- Easy to deploy and maintain: VXLAN only needs to be deployed on the edge devices of the transport network. Devices in the transport network perform typical layer 3 forwarding.
- Scalability: Can support up to 16 million logical networks.
- Flexibility: Allows for workload mobility across data centers.
- Multi-tenancy: Ideal for cloud environments that need to isolate traffic for different tenants.
Why VXLAN is Important in Modern Data Centers
- Overcoming the limitations of VLANs:
- Traditional VLANs struggle with scalability and flexibility in large environments.
- Enablement of hybrid and multi-cloud networks:
- VXLAN makes it easier to connect data centers with cloud providers or multiple cloud regions.
- Support for microservices and containers:
- In Kubernetes and other container-based environments, VXLAN provides the required network isolation and scalability.
How it works
The vxlan encapsulates Layer 2 Ethernet frames in Layer 4 UDP packets, enabling you to create virtualized Layer 2 subnets that span physical Layer 3 networks. The entity that performs the encapsulation and decapsulation of packets is called the VXLAN Tunnel Endpoint (VTEP). A VTEP can be an independent network device, such as a physical router or switch, or a virtual switch deployed on a server. VTEPs encapsulate Ethernet frames into VXLAN packets, which are then sent to the destination VTEP over an IP or other Layer 3 network, where they’re decapsulated and forwarded to the destination server.
Key components
- VTEPs: The device that originates and terminates the VXLAN tunnel, and maps a VLAN to a VNI and a VNI to a VLAN.
- VNI:is used to uniquely identify the VXLAN. The VNI is similar to a VLAN ID, but having 24 bits allows you to create many more VXLANs than VLANs.
- VXLAN Tunnel: The logical connection between two VTEPs.
- Network Virtual Interface (NVE): Logical interface where the encapsulation and de-encapsulation occur.
The Role of NVIDIA's New Switches in VXLAN Implementation
- NVIDIA’s entry into networking hardware:
- NVIDIA is enhancing its role in high-performance networking.
- Their new switches, such as the NVIDIA Spectrum family, are built to handle modern networking requirements, including VXLAN support.
Why NVIDIA Switches Excel with VXLAN
- High Throughput and Low Latency:
- NVIDIA's switches are optimized for low-latency networking and high throughput, critical for large-scale VXLAN deployments.
- Advanced VXLAN Offloading:
- The switches support hardware-based VXLAN offloading, reducing the burden on the CPU and improving overall network performance.
- End-to-End Visibility and Automation:
- NVIDIA’s network solutions integrate with its software-defined networking (SDN) tools, providing better visibility, automation, and control in VXLAN environments.
- Support for AI and GPU Workloads:
- NVIDIA switches are designed to support AI workloads, making them perfect for data centers handling both VXLAN and high-performance computing.
Key Advantages Over Competitors
- Integration with GPU-driven workloads:
- NVIDIA’s focus on AI, combined with its high-performance network switches, provides seamless integration between computing and networking.
- Scalability and Future-Proofing:
- With hardware that is designed for the future of AI-driven networking and VXLAN, NVIDIA is positioned to handle the growth of data and compute power needs.
Conclusion
- VXLAN is crucial for the modern data center.
- NVIDIA’s new switches provide the perfect balance of performance, scalability, and automation for VXLAN deployments.
- Looking ahead: With NVIDIA's deep integration between AI, GPUs, and networking, they are a key player in the future of data center technology.
Related links:
https://www.juniper.net/us/en/research-topics/what-is-vxlan.html
https://www.nvidia.com/en-us/networking/ethernet-switching/