Network Virtualization using Generic Routing Encapsulation (NVGRE) is a technology designed to address scalability issues in large cloud computing environments. It uses Generic Routing Encapsulation (GRE) to tunnel Layer 2 packets over Layer 3 networks.
How NVGRE Works
• Encapsulation: NVGRE encapsulates a virtual machine’s packet inside another packet. The outer packet has the source and destination provider addresses, while the inner packet contains the original data.
• Virtual Subnet ID (VSID): A 24-bit VSID is included in the GRE header, which helps in identifying the virtual network to which the packet belongs.
• Isolation: This encapsulation allows multiple virtual networks to coexist on the same physical network infrastructure without interfering with each other.
Practical Use Cases of NVGRE
1. Multi-Tenant Data Centers: NVGRE is widely used in data centers that host multiple tenants. It provides isolation and concurrency between different tenants’ networks, ensuring that each tenant’s data remains secure and separate.
2. Cloud Computing: In large cloud environments, NVGRE helps in managing and scaling virtual networks efficiently. It allows for the creation of numerous virtual networks without the limitations of traditional VLANs.
3. Disaster Recovery: NVGRE can be used to create virtual networks that span multiple physical locations, facilitating disaster recovery solutions by ensuring that virtual machines can be moved seamlessly between data centers.
4. Load Balancing: By encapsulating traffic, NVGRE supports load balancing across multiple servers, improving the performance and reliability of applications hosted in virtualized environments