THIS POST IS A PLACEHOLDER AND NOT A PROPER POST
⚠️ Heads-up for Azure architects and engineers:
Microsoft is retiring default outbound internet access for VMs and Virtual Networks. This post breaks down what’s changing, why it matters, and what you need to do to stay connected and compliant.
📅 Key Dates
- September 30, 2025 — Default outbound access removed for new VMs in existing VNets.
- March 31, 2026 — Newly created VNets will default to private subnets with no implicit internet access.
🔍 What’s Changing
Historically, Azure allowed VMs without public IPs to reach the internet via a shared, unmanaged IP. This “default outbound access” was convenient—but unpredictable and insecure.
Microsoft is removing this behavior in two phases:
- VM-level change (Sep 2025): New VMs won’t get outbound access unless explicitly configured.
- VNet-level change (Mar 2026): New VNets will default to private subnets, requiring explicit outbound paths.
🧠 Why This Matters
Azure is doubling down on its secure-by-default posture:
- Implicit egress paths obscure IP ownership and complicate firewall rules.
- Explicit outbound methods (Public IP, NAT Gateway, Load Balancer) give you control and traceability.
- Predictable IPs simplify NSGs, partner integrations, and compliance audits.
🛠 What You Need to Do
1. Audit Your Deployments
- Identify workloads using default outbound access.
- Review ARM, Bicep, Terraform templates for missing outbound config.
2. Choose Your Egress Strategy
| Method | Use Case | Pros |
|---|---|---|
| Public IP | Direct access, full port control | Simple, transparent |
| NAT Gateway | High-scale SNAT, shared outbound IP | Scalable, cost-effective |
| Load Balancer | Already fronting VMs, outbound rule support | Reuse existing infrastructure |
3. Update Your IaC and Pipelines
- Embed outbound config in templates now.
- Test deployments post–September 2025 and March 2026.
4. Review Network Security
- Align NSGs and firewalls with new outbound IPs.
- Update partner integrations that rely on static IPs.
✅ Best Practices
- Define outbound strategy per workload.
- Validate changes in dev/test environments.
- Document new patterns in runbooks and onboarding guides.
- Tag resources by egress method for cost and policy tracking.
📚 References
- Azure Update: Default outbound access retirement
- Cato Networks: Microsoft Changing Default Outbound Access
- AzurePro Deep Dive
By planning ahead, you’ll avoid last-minute surprises and ensure your workloads stay connected, secure, and compliant. Let’s architect with intention.