VNI (VXLAN ID)

The VXLAN ID, also known as the VXLAN Network Identifier (VNI), plays a crucial role in VXLAN technology. Here are the key points about VXLAN ID (VNI):

1. Purpose: The VXLAN ID is a 24-bit identifier used within VXLAN encapsulation to uniquely identify VXLAN segments or virtual Layer 2 networks across a Layer 3 infrastructure.

2. Range: The 24-bit VXLAN ID allows for a much larger number of unique identifiers compared to VLANs. Specifically, VXLAN supports up to 16 million (2^24) VXLAN segments (VXLAN IDs), whereas VLANs are limited to 4096 (2^12).

3. Encapsulation: In VXLAN, Layer 2 Ethernet frames are encapsulated within UDP packets with VXLAN headers. The VXLAN ID is a critical component of this header, helping to differentiate between different VXLAN segments.

4. Mapping: VXLAN IDs are used to map virtual networks or segments onto the underlying physical network. This mapping can be statically configured or dynamically managed by a VXLAN controller or through protocols like BGP (Border Gateway Protocol) EVPN (Ethernet Virtual Private Network).

5. Flexibility: The large number of available VXLAN IDs allows for flexible network virtualization and segmentation in environments such as data centers and cloud computing. It facilitates scalable multi-tenancy and enhances workload mobility across physical boundaries.

6. Operational Considerations: Administrators need to ensure VXLAN IDs are unique within their VXLAN domain to avoid segmentation or connectivity issues. However, VXLAN IDs themselves do not have to be globally unique across different VXLAN deployments.

Overall, the VXLAN ID (VNI) is a fundamental component of VXLAN technology, enabling efficient and scalable overlay networks that extend Layer 2 connectivity over Layer 3 networks.