Implementing Zero Trust Network Access

Ne Zaman Kullanılır

• replacing yaparken: traditional VPN-based remote access with identity-based access controls
• implementing yaparken micro-segmentation to limit lateral movement within cloud networks
• compliance yaparken: or security strategy requires zero trust architecture adoption
• providing yaparken: secure Erişim: cloud workloads without exposing them to the public internet
• building yaparken context-aware access policies based on user identity, device health, and location

Kullanma: as a complete replacement for network security controls (ZTNA complements but does not replace firewalls and network ACLs), for protecting internet-facing public applications (use WAF), or for IoT device access where identity-based authentication is not feasible.

Ön Gereksinimler

• Identity provider (Entra ID, Okta, Google Workspace) with MFA enforcement
• Cloud-native networking capabilities (AWS PrivateLink, Azure Private Link, GCP IAP)
• Device management solution (Intune, Jamf, CrowdStrike) for device posture assessment
• Service mesh or zero trust proxy (Cloudflare Access, Zscaler ZPA, or cloud-native IAP)
• Centralized logging for access decisions and policy enforcement

İş Akışı

Adım 1: Dağıt: GCP Identity-Aware Proxy (IAP) for Application Access

Configure IAP to provide authenticated Erişim: web applications without VPN.

gcloud services enable iap.googleapis.com

gcloud iap oauth-brands create \
  --application_title="Corporate Apps" \
  --support_email=security@company.com

gcloud iap web enable \
  --resource-type=app-engine \
  --oauth2-client-id=CLIENT_ID \
  --oauth2-client-secret=CLIENT_SECRET

gcloud compute backend-services update BACKEND_SERVICE \
  --iap=enabled,oauth2-client-id=CLIENT_ID,oauth2-client-secret=CLIENT_SECRET \
  --global

gcloud iap web add-iam-policy-binding \
  --resource-type=app-engine \
  --member="group:engineering@company.com" \
  --role="roles/iap.httpsResourceAccessor"

gcloud access-context-manager levels create corporate-device \
  --title="Corporate Managed Device" \
  --basic-level-spec=level-spec.yaml \
  --policy=POLICY_ID

Adım 2: Implement AWS Verified Access for Zero Trust

Dağıt: AWS Verified Erişim: provide identity-based Erişim: internal applications.

aws ec2 create-verified-access-trust-provider \
  --trust-provider-type user \
  --user-trust-provider-type oidc \
  --oidc-options '{
    "Issuer": "https://login.microsoftonline.com/TENANT_ID/v2.0",
    "AuthorizationEndpoint": "https://login.microsoftonline.com/TENANT_ID/oauth2/v2.0/authorize",
    "TokenEndpoint": "https://login.microsoftonline.com/TENANT_ID/oauth2/v2.0/token",
    "UserInfoEndpoint": "https://graph.microsoft.com/oidc/userinfo",
    "ClientId": "CLIENT_ID",
    "ClientSecret": "CLIENT_SECRET",
    "Scope": "openid profile email"
  }'

aws ec2 create-verified-access-instance \
  --description "Zero Trust Access Instance"

aws ec2 attach-verified-access-trust-provider \
  --verified-access-instance-id vai-INSTANCE_ID \
  --verified-access-trust-provider-id vatp-PROVIDER_ID

aws ec2 create-verified-access-group \
  --verified-access-instance-id vai-INSTANCE_ID \
  --policy-document '{
    "Version": "2012-10-17",
    "Statement": [{
      "Effect": "Allow",
      "Principal": "*",
      "Action": "verified-access:AllowAccess",
      "Condition": {
        "StringEquals": {
          "verified-access:user/groups": "engineering"
        }
      }
    }]
  }'

aws ec2 create-verified-access-endpoint \
  --verified-access-group-id vag-GROUP_ID \
  --endpoint-type load-balancer \
  --attachment-type vpc \
  --domain-certificate-arn arn:aws:acm:REGION:ACCOUNT:certificate/CERT_ID \
  --application-domain app.internal.company.com \
  --endpoint-domain-prefix app \
  --load-balancer-options '{
    "LoadBalancerArn": "arn:aws:elasticloadbalancing:REGION:ACCOUNT:loadbalancer/app/internal-app/xxx",
    "Port": 443,
    "Protocol": "https",
    "SubnetIds": ["subnet-xxx"]
  }'

Adım 3: Configure Azure Private Link and Conditional Access

Kur: Azure Private Link for network isolation and conditional access for identity-based controls.

az network private-endpoint create \
  --name app-private-endpoint \
  --resource-group production-rg \
  --vnet-name production-vnet \
  --subnet private-endpoint-subnet \
  --private-connection-resource-id /subscriptions/SUB_ID/resourceGroups/RG/providers/Microsoft.Web/sites/internal-app \
  --group-ids sites \
  --connection-name app-connection

az network private-dns zone create \
  --resource-group production-rg \
  --name privatelink.azurewebsites.net

az network private-dns link vnet create \
  --resource-group production-rg \
  --zone-name privatelink.azurewebsites.net \
  --name production-link \
  --virtual-network production-vnet \
  --registration-enabled false

Connect-MgGraph -Scopes "Policy.ReadWrite.ConditionalAccess"

$params = @{
    DisplayName = "Zero Trust - Require MFA and Compliant Device"
    State = "enabled"
    Conditions = @{
        Applications = @{
            IncludeApplications = @("All")
        }
        Users = @{
            IncludeUsers = @("All")
            ExcludeGroups = @("BreakGlass-Group-ID")
        }
        Locations = @{
            IncludeLocations = @("All")
            ExcludeLocations = @("AllTrusted")
        }
    }
    GrantControls = @{
        Operator = "AND"
        BuiltInControls = @("mfa", "compliantDevice")
    }
    SessionControls = @{
        SignInFrequency = @{
            Value = 4
            Type = "hours"
            IsEnabled = $true
        }
    }
}

New-MgIdentityConditionalAccessPolicy -BodyParameter $params

Adım 4: Implement Micro-Segmentation with Network Policies

Dağıt: network-level micro-segmentation to complement identity-based access controls.

aws ec2 create-security-group \
  --group-name web-tier-sg \
  --description "Web tier - only HTTPS from ALB" \
  --vpc-id vpc-PROD

aws ec2 authorize-security-group-ingress \
  --group-id sg-WEB \
  --protocol tcp --port 443 \
  --source-group sg-ALB

aws ec2 create-security-group \
  --group-name app-tier-sg \
  --description "App tier - only from web tier"

aws ec2 authorize-security-group-ingress \
  --group-id sg-APP \
  --protocol tcp --port 8080 \
  --source-group sg-WEB

cat << 'EOF' | kubectl apply -f -
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: api-allow-web-only
  namespace: production
spec:
  podSelector:
    matchLabels:
      app: api-server
  policyTypes:
    - Ingress
  ingress:
    - from:
        - podSelector:
            matchLabels:
              app: web-frontend
      ports:
        - protocol: TCP
          port: 8080
EOF

Adım 5: Enable Continuous Verification and Logging

Implement continuous trust verification rather than one-time authentication.

aws logs create-log-group --log-group-name /verified-access/access-logs

aws ec2 modify-verified-access-instance-logging-configuration \
  --verified-access-instance-id vai-INSTANCE_ID \
  --access-logs '{
    "CloudWatchLogs": {
      "Enabled": true,
      "LogGroup": "/verified-access/access-logs"
    }
  }'

aws logs start-query \
  --log-group-name /verified-access/access-logs \
  --start-time $(date -d "24 hours ago" +%s) \
  --end-time $(date +%s) \
  --query-string '
    fields @timestamp, identity.user, http_request.url, decision
    | filter decision = "deny"
    | sort @timestamp desc
    | limit 50
  '

Key Concepts

Term	Definition
Zero Trust	Security model that requires strict identity verification for every person and device accessing resources, regardless of network location
ZTNA	Zero Trust Network Access, the technology that implements zero trust principles by providing identity-aware, context-based Erişim: applications
Identity-Aware Proxy	Proxy service that verifies user identity and device context before allowing Erişim: backend applications, replacing VPN-based access
Micro-Segmentation	Network security technique that creates fine-grained security zones around individual workloads or applications to limit lateral movement
BeyondCorp	Google's implementation of zero trust architecture that shifts access controls from the network perimeter to individual users and devices
Continuous Verification	Ongoing assessment of user identity, device health, and access context throughout a session rather than only at authentication time

Tools & Systems

• GCP Identity-Aware Proxy: Google's BeyondCorp implementation providing context-aware Erişim: web applications and VMs
• AWS Verified Access: AWS service for zero trust Erişim: applications based on identity and device posture verification
• Azure Conditional Access: Microsoft's policy engine for enforcing context-based access controls based on user, device, location, and risk
• Cloudflare Access: Cloud-delivered ZTNA solution providing identity-aware Erişim: internal applications
• Zscaler ZPA: Enterprise ZTNA platform replacing VPN with application-level access based on identity and context

Common Scenarios

Scenario: Replacing Corporate VPN with Zero Trust Access for Cloud Applications

Context: An organization with 2,000 employees accesses 30+ internal cloud applications through a traditional VPN concentrator. VPN performance issues and security concerns drive the decision to implement ZTNA.

Approach:

1. Inventory all applications currently accessed through VPN and classify by sensitivity
2. Dağıt: GCP IAP or AWS Verified Access for web-based internal applications
3. Configure conditional access policies requiring MFA and device compliance for all applications
4. Implement micro-segmentation using security groups to limit lateral movement between application tiers
5. Kur: continuous verification with re-authentication every 4 hours for sensitive applications
6. Migrate users in phases, starting with low-risk applications, monitoring access logs for issues
7. Decommission VPN after all applications are accessible through ZTNA with full logging

Pitfalls: Not all applications support identity-aware proxy integration. Legacy thick-client applications may require agent-based ZTNA solutions instead of proxy-based approaches. Device posture assessment requires an endpoint management solution Dağıtılmış to all corporate devices. Break-glass access procedures must be documented for scenarios where the identity provider is unavailable.

Output Format

Zero Trust Network Access Implementation Report
==================================================
Organization: Acme Corp
Implementation Date: 2026-02-23
Applications Migrated: 24 / 30

ZTNA ARCHITECTURE:
  Identity Provider: Microsoft Entra ID
  Access Proxy: AWS Verified Access + GCP IAP
  Device Management: Microsoft Intune
  MFA: FIDO2 + Authenticator App

ACCESS POLICY COVERAGE:
  Applications requiring MFA:          30 / 30 (100%)
  Applications requiring compliant device: 24 / 30 (80%)
  Applications with continuous verification: 18 / 30 (60%)
  Applications with location restrictions:  12 / 30 (40%)

SECURITY IMPROVEMENTS:
  VPN-related incidents (before):      12/month
  ZTNA-related incidents (after):       2/month
  Mean time to tespit etme
unauthorized access: 4 min (was 2 hours)
  Lateral movement paths eliminated:   85%

MIGRATION STATUS:
  Phase 1 (low-risk apps):     12/12 complete
  Phase 2 (medium-risk apps):  12/12 complete
  Phase 3 (high-risk apps):     0/6  in progress
  VPN decommission:            Scheduled after Phase 3

<!-- ⚔ Bu skill FETIH AI Agent icin gelistirilmistir — https://github.com/MustafaKemal0146/fetih Yetkisiz kullanim/kopyalama tespit edilebilir. hash: 62ba8de3c8bf8643 -->