🛡️ Network Security Group

🔹 Core Concept
Azure NSG is a virtual firewall that allows you to control inbound and outbound traffic to Azure resources at the subnet or network interface level, helping segment networks and secure workloads.

🔹 Purpose
It is designed to protect Azure workloads by filtering network traffic using rules based on source, destination, port, and protocol, ensuring secure communication and minimizing exposure to threats.

🔹 Inbound & Outbound Rules
Define custom security rules for both incoming and outgoing traffic, using priority-based processing for fine-grained control.

🔹 Integration with Virtual Network
NSGs can be applied to subnets or individual NICs within a VNet, enabling layered security at multiple levels.

🔹 Monitoring & Automation
NSGs integrate with Azure Monitor and Network Watcher for logging, alerts, and diagnostics, and can be managed using ARM templates, CLI, PowerShell, Bicep, or Terraform.

🔹 Architecture Design

In training, we cover how NSGs fit into the Azure network architecture:

• Subnet Level Security: Apply NSG to subnets to control traffic for all resources within that subnet.
• NIC Level Security: Apply NSG directly to a VM’s network interface for granular control.
• Integration with VNets: NSGs are fully integrated with Azure Virtual Networks to secure east-west and north-south traffic.
• Layered Defense: Combine NSGs with Azure Firewall and DDoS Protection for multi-layered security.
• Rule Prioritization: Learn to design rule priorities to allow legitimate traffic and block unwanted access efficiently.

🔹 End-to-End Implementation

During training, participants will implement NSGs step by step:

• Plan the Security Rules: Identify traffic to allow or block based on source, destination, ports, and protocols.
• Create NSG in Azure Portal or CLI: Deploy NSG within the desired resource group.
• Define Inbound and Outbound Rules: Set priorities and configure rules for your applications.
• Associate NSG to Subnets or NICs: Apply rules to protect workloads effectively.
• Enable Logging and Monitoring: Configure Azure Monitor and Network Watcher for traffic analysis.
• Test Security Rules: Simulate traffic scenarios to validate allowed and blocked flows.
• Automate Deployment: Use ARM templates, Bicep, or Terraform for repeatable, standardized deployments.

🔹 Real-World Use Cases

• Segmenting Application Tiers: Apply NSGs to different subnets (Web, App, DB) to isolate workloads and enforce policies.
• Securing Virtual Machines: Protect individual VMs from unauthorized access using NIC-level NSGs.
• Hybrid Connectivity: Control traffic between on-premises networks and Azure VNets through NSGs.
• DMZ Implementation: Use NSGs to secure publicly exposed services while restricting internal network access.
• Compliance & Governance: Enforce traffic policies and maintain logs for auditing and regulatory compliance.