Implementing network segmentation with Virtual LANs (VLANs) is a fundamental and highly effective measure for enforcing tenant partitioning. By assigning each tenant to a unique VLAN, their network traffic is logically isolated at Layer 2 of the OSI model. This segregation prevents direct communication between tenants' resources, contains broadcast traffic within each tenant's virtual network, and forms a crucial boundary for applying access control policies via firewalls and routers. This directly addresses the core requirement of preventing unauthorized access and data leakage between tenants in a multi-tenant architecture.

A. Disabling logging and monitoring critically undermines security by removing the ability to detect, investigate, and respond to unauthorized access attempts or policy violations.

B. A common management interface without strict, tenant-aware access controls is a major security flaw that could easily lead to cross-tenant data exposure or misconfiguration.

C. Using shared storage without access controls completely violates the principles of confidentiality and isolation, allowing any tenant to read, modify, or delete another's data.

1. National Institute of Standards and Technology (NIST) Special Publication 800-125B

Secure Virtual Network Configuration for Virtual Machine (VM) Protection

Section 4.2

"Virtual Network-Based Protections

" states: "VLANs are a common mechanism for creating isolated virtual local area networks (VLANs) on a physical local area network (LAN)... This allows VMs on the same VLAN to communicate with each other as if they were on the same physical LAN segment

while preventing them from communicating with VMs on different VLANs at the data link layer."

2. Ruirui

Z.

& Zhibin

Z. (2010). The Security of Multi-tenancy in Cloud Computing. In 2010 International Conference on Computer Application and System Modeling (ICCASM 2010) (Vol. 9

pp. V9-229). This paper discusses isolation as a key security requirement in multi-tenancy

noting that "Network isolation is usually achieved by VLANs

which can isolate broadcast domains." (Section 3

Paragraph 2). DOI: 10.1109/ICCASM.2010.5620522

3. Cloud Security Alliance (CSA). Security Guidance for Critical Areas of Focus in Cloud Computing v4.0

Domain 1: Cloud Computing Concepts and Architectures

Section on "Multi-Tenancy

" discusses the importance of isolation controls. It implicitly supports segmentation by stating that logical isolation mechanisms are essential to prevent tenants from accessing each other's resources

with network controls being a primary example.