Which statement about VXLAN is true?
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A. B. C. D.A.
VXLAN (Virtual Extensible LAN) is a network virtualization technology that provides Layer 2 connectivity between distant sites over an IP network. It addresses the limitations of VLANs (Virtual Local Area Networks), which have a limited number of IDs and cannot span beyond a single Layer 2 domain.
Out of the given options, the correct statement about VXLAN is:
A. VXLAN encapsulates a Layer 2 frame in an IP-UDP header, which allows Layer 2 adjacency across router boundaries.
Explanation:
VXLAN encapsulates the original Layer 2 Ethernet frame inside an IP-UDP header, which enables the Layer 2 frame to travel across an IP network. The UDP header contains the VXLAN Network Identifier (VNI), which is a 24-bit field that identifies the VXLAN segment. This allows multiple Layer 2 segments to coexist over the same physical network infrastructure, with each segment identified by a unique VNI.
VXLAN uses an overlay network architecture to enable communication between endpoints on different Layer 2 domains. The original Layer 2 frame is encapsulated with a VXLAN header, which adds an extra 50 bytes of overhead to the frame. The resulting packet is then forwarded across the physical network as an IP packet.
VXLAN is often used in data center environments to provide network virtualization across multiple physical servers and switches. It allows the creation of virtual networks that can span across physical boundaries, enabling applications to communicate as if they are on the same Layer 2 network.
B. VXLAN does not use the Spanning Tree Protocol (STP) for loop prevention. Instead, it uses a flood-and-learn mechanism to discover the MAC addresses of endpoints within a VXLAN segment.
C. VXLAN extends the Layer 2 Segment ID field to 24-bits, which allows up to 16 million unique Layer 2 segments over the same network, not 4094 as stated in the option.
D. VXLAN does not use TCP as the transport protocol over the physical data center network. It uses UDP as the transport protocol, which provides a more lightweight and scalable solution.