Architect Multi-Tenant Zero-Trust Network and Service Segmentation

Duration: ~30 minutes

Overview

Design and implement a comprehensive zero-trust network architecture for multi-tenant OpenShift environments. You will architect service mesh mutual TLS (mTLS), implement layered NetworkPolicies, configure multi-network CNIs, establish egress governance, and apply zero-trust patterns to ensure complete network segmentation and isolation.

Design layered zero-trust networking with NetworkPolicies, mTLS, and egress controls, then validate that tenants and services stay isolated.

Why it matters

Multi-tenant environments require strict network isolation to prevent lateral movement and data exfiltration. Zero-trust networking assumes no implicit trust between services, requiring verification for every connection. This lab demonstrates how to architect a comprehensive zero-trust network that protects against:

  • Lateral movement attacks

  • Unauthorized service-to-service communication

  • Data exfiltration through uncontrolled egress

  • Network-based privilege escalation

  • Cross-tenant data access

What does it solve

Traditional network security relies on perimeter defense and implicit trust within the network. Zero-trust architecture eliminates these assumptions by:

  • Requiring authentication and authorization for every connection

  • Implementing micro-segmentation at the service level

  • Enforcing least-privilege network access

  • Providing visibility into all network flows

  • Enabling granular policy enforcement

Your Mission

Assume a foothold will try lateral movement. Build layered NetworkPolicies, mTLS, and egress controls that keep tenants and services isolated even when one pod is owned.

Understanding the Architecture

Component Purpose OpenShift/K8s Implementation

Service Mesh mTLS

Encrypt and authenticate all service-to-service traffic

Service Mesh (Istio/OSSM) with mTLS enabled

Layered NetworkPolicies

Defense-in-depth network segmentation

Multiple NetworkPolicy layers (namespace, pod, service)

Multi-Network CNIs

Isolated network planes for different workloads

Multus CNI with multiple network attachments

Egress Governance

Control and monitor outbound traffic

Egress NetworkPolicies, EgressIP, Egress Firewall

Zero-Trust Patterns

No implicit trust, verify everything

Policy-driven access control at every layer

Lab Content

This lab is currently under development. Content will include:

  • Service mesh configuration and mTLS setup

  • NetworkPolicy design patterns and implementation

  • Multus CNI configuration for multi-network scenarios

  • Egress governance policies and controls

  • Zero-trust architecture validation and testing

Prerequisites

  • OpenShift cluster with cluster-admin access

  • Service Mesh Operator installed

  • Multus CNI plugin available

  • Understanding of NetworkPolicies and service mesh concepts

Debrief

Multi-tenant zero-trust networking assumes a foothold and designs layered stop-points: NetworkPolicies, mesh mTLS, Multus/egress governance—not a single flat allow.

What this module targets:

  • Tenant segmentation blueprints

  • Service mesh mTLS and identity-aware paths

  • Egress and multi-network controls

Until full exercises land: draw your east-west trust zones and mark where default-deny already exists versus open namespaces.

giphy

Cleanup

Before moving to the next module, run the lab cleanup script to reset transient resources from this module.

cd ~/openshift-security-roadshow
bash setup/lab-cleanup.sh --module 301-03