ISC2 CISSP (Certified Information Systems Security Professional)Communication and Network SecurityHard
A cloud service provider is designing its data center network infrastructure to support multi-tenant environments. The design must ensure that each tenant's traffic is completely isolated from other tenants, even when sharing the same physical network hardware, and that network services can be rapidly provisioned and scaled. Which of the following networking technologies is BEST suited for achieving this scalable, isolated multi-tenancy?
- AMultiprotocol Label Switching (MPLS)
- BVirtual Private Network (VPN)
- CNetwork Function Virtualization (NFV)
- DVirtual Extensible LAN (VXLAN)
Show answer & explanationAnswer & explanation
Correct answer: D. Virtual Extensible LAN (VXLAN)
VXLAN (Virtual Extensible LAN) is a network virtualization technology that encapsulates Layer 2 Ethernet frames within Layer 3 IP packets. This allows for the creation of logical, isolated Layer 2 networks (segments) across a shared Layer 3 infrastructure, enabling scalable multi-tenancy in large data centers and cloud environments without the traditional VLAN limits.
Why the other options are wrong
- A. MPLS is for high-performance forwarding and traffic engineering, not primarily for scalable multi-tenant isolation within a data center.
- B. VPNs are for secure remote access or site-to-site connectivity, not for scalable multi-tenant segmentation within a data center.
- C. NFV virtualizes network services (e.g., firewalls), but doesn't inherently provide the underlying network segmentation for multi-tenancy.
Virtual Extensible LAN (VXLAN)
A network virtualization technology that encapsulates Layer 2 Ethernet frames in Layer 3 IP packets, creating a logical Layer 2 network over an existing Layer 3 infrastructure. It enables scalable multi-tenancy and larger virtual network segments in cloud data centers.
- Extends Layer 2 networks over Layer 3 (referred to as an overlay network).
- Uses a 24-bit VXLAN Network Identifier (VNI) for up to 16 million logical networks.
- Solves the scalability limitations of traditional VLANs (4096 IDs).
- Enables flexible, isolated multi-tenant environments in cloud data centers.
Memory trick: VXLAN Virtually eXtends LANs for All Tenants.