SDA Tunneling

C.

The correct answer is C. Virtual Extensible LAN (VXLAN).

In Software Defined Access (SDA), VXLAN is used to provide a tunnel between two edge nodes in different fabrics. VXLAN is an encapsulation protocol that is used to create virtualized Layer 2 networks over an existing Layer 3 network. VXLAN allows for the creation of virtualized networks that span multiple physical switches or fabrics. VXLAN packets are encapsulated in UDP packets, which allows them to traverse Layer 3 networks.

VXLAN uses a 24-bit Segment ID (VNI) to identify the virtual network. When a packet is sent from a VXLAN endpoint, the VNI is added to the packet header, along with the VXLAN header and the original Ethernet frame. The packet is then encapsulated in a UDP packet and sent across the network.

When the packet reaches its destination, the VXLAN header is stripped off, and the original Ethernet frame is delivered to the endpoint. This allows for the creation of a virtualized Layer 2 network that spans multiple physical switches or fabrics.

In contrast, Generic Router Encapsulation (GRE) is an encapsulation protocol that creates a private, secure tunnel between two endpoints over a public network. GRE is typically used to encapsulate non-IP protocols over an IP network.

Virtual Local Area Network (VLAN) is a technique that allows multiple networks to coexist on the same physical switch or network. VLANs are used to segment networks, improve security, and improve network performance.

Point-to-Point Protocol (PPP) is a data link protocol that is used to establish a direct connection between two nodes over a serial interface. PPP is typically used to connect a computer to an Internet Service Provider (ISP) over a telephone line.