Encapsulation protocols are used to create overlay networks that provide connectivity over an underlying network. Let's analyze each option:
A . VLAN
Incorrect: VLANs operate at Layer 2 and are limited to a single physical network. They do not provide tunneling or overlay capabilities over a Layer 3 network.
B . IPsec
Incorrect: IPsec is a security protocol used to encrypt and authenticate IP packets. It does not provide Layer 2 overlay capabilities.
C . VXLAN
Correct: VXLAN (Virtual Extensible LAN) is an encapsulation protocol that creates a Layer 2 overlay network over an underlying Layer 3 network. It encapsulates Layer 2 Ethernet frames within UDP packets, enabling scalable and flexible network architectures.
D . GRE
Incorrect: GRE (Generic Routing Encapsulation) is a tunneling protocol that encapsulates packets but does not inherently provide Layer 2 overlay capabilities. It is typically used for point-to-point tunnels.
Why VXLAN?
Layer 2 Overlay: VXLAN extends Layer 2 networks across Layer 3 boundaries, enabling seamless communication between distributed environments.
Scalability: VXLAN supports up to 16 million virtual networks, making it ideal for large-scale cloud deployments.
JNCIA Cloud Reference:
The JNCIA-Cloud certification covers overlay networking protocols like VXLAN as part of its curriculum on cloud architectures. Understanding VXLAN is essential for designing scalable and resilient virtual networks.
For example, Juniper Contrail uses VXLAN to extend virtual networks across data centers, ensuring consistent connectivity and isolation.
Reference:
VXLAN RFC 7348
Juniper JNCIA-Cloud Study Guide: Overlay Networking