Azure Network Watcher & Topology: Visualizing and Monitoring Azure Networking
By Pooja | 9th July 2025
Introduction
In cloud environments, particularly Microsoft Azure, networking is a foundational pillar for application delivery, security, and performance. As cloud deployments become more complex—with virtual machines, subnets, load balancers, gateways, and firewalls—monitoring and troubleshooting network-related issues becomes crucial.
Enter Azure Network Watcher, a comprehensive suite of tools designed to help you monitor, diagnose, and visualize your networking infrastructure. One of its standout features is Topology, which gives you an instant visual representation of your network layout.
This article explores Azure Network Watcher and Topology, guiding you through its architecture, tools, and how to use it effectively to manage your Azure network resources.
What is Azure Network Watcher?
Azure Network Watcher is a regional service that provides a set of tools to monitor and diagnose network conditions at the infrastructure level in Azure. It gives visibility into:
- Communication between resources
- Network configuration and health
- Packet flows
- Topological view of network architecture
You can monitor traffic patterns, validate network configurations, capture packets, and troubleshoot connectivity from within the Azure Portal or using CLI/PowerShell.
Why Use Azure Network Watcher?
Azure Network Watcher helps organizations:
- Diagnose connectivity issues between virtual machines
- Visualize the entire virtual network topology
- Verify and audit NSG rules
- Capture traffic at the packet level for deep inspection
- Track outbound and inbound traffic flows
- Monitor latency between locations
In short, it reduces the time spent troubleshooting network issues, enhances performance visibility, and supports proactive monitoring.
Core Capabilities of Network Watcher
Azure Network Watcher has multiple functional areas:
- Monitoring
Monitor connectivity and performance between VMs, on-premises to Azure, or Azure to Azure across regions.
- Diagnostics
Run diagnostic checks on virtual machines, network interfaces, security groups, and connections to verify proper configuration.
- Logging
Capture flow logs from Network Security Groups and packet-level data for security auditing and analytics.
- Visualization
See your Azure network in a diagrammatic form to understand the architecture and dependencies.
Azure Network Topology Overview
What is Topology in Azure Network Watcher?
Topology provides a visual map of your virtual network environment, showing how resources like:
- Virtual Machines
- Subnets
- Network Interfaces
- Load Balancers
- Gateways
- Application Security Groups
are connected to each other.
You can interact with each component in the diagram, view metadata, and identify potential configuration errors.
Why It Matters:
- Simplifies understanding of large and complex environments
- Supports troubleshooting by showing missing or misconfigured connections
- Helps during audits and documentation of network infrastructure
- Useful during compliance checks or migration assessments
Enabling Network Watcher
Network Watcher is enabled by default in most Azure subscriptions when a Virtual Network is created. You can verify or enable it manually:
Steps via Azure Portal:
- Go to “Network Watcher” under All Services
- Click “Regions”
- Ensure your target region has Network Watcher enabled
- If not, click “Enable”
Alternatively, you can use Azure CLI:
bash
CopyEdit
az network watcher configure –locations “eastus” –enabled true –resource-group MyResourceGroup
Using Topology in Network Watcher
How to Access Topology View
- Navigate to Network Watcher in the Azure Portal
- Click on “Topology”
- Select:
- Subscription
- Resource Group
- Virtual Network (VNet)
The topology diagram is generated for that VNet.
Interpreting the Topology View
The visual layout includes:
- VNet in the center
- Connected subnets
- Network interfaces and VMs
- Public IPs, Load Balancers, Gateways
- NSG associations
You can click on any component to view:
- IP addresses
- Associated NSG
- VM instance size
- Connected disks and interfaces
The “Export” button allows you to download the layout as a JSON file.
Other Tools in Azure Network Watcher
Connection Monitor
- Monitors network connectivity between endpoints
- Visualizes packet loss, latency, and availability
- Supports hybrid networks (Azure + on-premises)
- IP Flow Verify
- Tests if traffic is allowed or denied to/from a VM
- Evaluates NSG rules and effective security settings
- NSG Flow Logs
- Captures all traffic that hits NSGs
- Useful for audits, threat detection, and compliance
- Packet Capture
- Captures network packets at NIC level for deep inspection
- Filter based on ports, protocols, or time
- Can be used with Wireshark or similar tools
- VPN Troubleshooting
- Provides diagnostics and logs for VPN Gateway and tunnels
- Checks status, connection attempts, and configuration errors
Integration with Azure Monitor and Log Analytics
Network Watcher integrates natively with:
- Azure Monitor – For metrics and alerts
- Log Analytics – For querying flow logs and traffic patterns
- Storage Accounts – To save logs and packet captures
- Azure Sentinel – For security operations and threat hunting
This integration enables end-to-end visibility, from application layer down to the network packet.
Security and Access Control
Network Watcher uses Role-Based Access Control (RBAC) to secure who can:
- View topology
- Start packet captures
- Access NSG flow logs
- Run diagnostics
You can assign roles like:
- Network Contributor
- Reader
- Security Reader
Always use least privilege access for sensitive data like packet captures or VPN logs.
Pricing and Considerations
Network Watcher is free to enable, but some features are billed:
Feature | Pricing Unit |
NSG Flow Logs | Per GB of logs |
Packet Capture | Storage usage + compute (if agent-based) |
Connection Monitor | Per test per month |
VPN Troubleshoot | Free (some data costs may apply) |
Topology View | Free |
Use Azure Pricing Calculator to estimate costs.
Real-world Use Cases
- Outage Troubleshooting
When a web app is down, use topology + IP Flow Verify to trace routing issues or misconfigured NSGs.
- Compliance Audits
Flow logs and topology are critical for proving firewall and security group policies to auditors.
- Incident Response
Use packet capture during suspicious activity to analyze traffic payloads and identify threats.
- Cloud Migration Planning
Visualize topology to ensure that migrated services are connected properly post-deployment.
Conclusion
Azure Network Watcher is a vital tool in the Azure ecosystem for monitoring, diagnosing, and visualizing network infrastructure. Its Topology feature stands out by offering a clear and interactive map of your virtual networks, making it easier for network engineers, security teams, and architects to understand resource connectivity and configurations.
By using Network Watcher’s full suite—connection monitors, flow logs, diagnostics, and packet captures—you gain end-to-end visibility into Azure networking, ensuring security, performance, and compliance across your environment.
Whether you’re managing a small development network or a multi-region production deployment, Network Watcher helps you stay informed, reduce downtime, and maintain robust networking practices in the cloud.