Azure Networking Monitoring - MSDN Documentation

Introduction to Azure Networking Monitoring

Effective monitoring of your Azure network is crucial for ensuring performance, availability, and security. This section outlines the key tools and techniques available to gain insights into your network traffic and resource health.

Azure provides a rich set of services and features designed to help you monitor your virtual networks, load balancers, firewalls, VPN gateways, and other network components. By leveraging these tools, you can proactively identify and resolve potential issues before they impact your applications and users.

Key Benefits of Monitoring:

Performance Optimization: Identify bottlenecks and optimize network throughput.
Security Assurance: Detect suspicious traffic patterns and potential security threats.
Availability Tracking: Ensure your network services are consistently available and responsive.
Cost Management: Understand data transfer costs and optimize resource utilization.
Troubleshooting: Quickly diagnose and resolve network connectivity issues.

Core Azure Monitoring Services for Networking

Azure offers several integrated services that are fundamental to monitoring your network infrastructure.

Azure Monitor

Azure Monitor is the foundational service for collecting, analyzing, and acting on telemetry from your Azure and on-premises environments. For networking, it provides:

Metrics: Numerical values that describe some aspect of a system at a particular point in time. Useful for performance indicators like bandwidth usage, latency, and connection counts.
Logs: Store and query diagnostic logs from various Azure networking resources.
Application Insights: While focused on applications, it can provide insights into network dependencies and performance from an application perspective.
Alerts: Configure rules to notify you when specific metric thresholds are breached or log events occur.

Network Watcher

Network Watcher is a service designed specifically for monitoring and diagnosing Azure network resources. It offers powerful tools for visualizing network traffic and diagnosing issues:

Connection Troubleshoot: Test connectivity between two virtual machines.
IP Flow Verify: Verify if traffic is allowed or denied to a VM's network interface based on NSG rules.
Next Hop: Determine the next hop to a destination IP address from a VM, useful for diagnosing routing issues.
Security Group View: View effective security rules applied to a VM.
Packet Capture: Capture network traffic for detailed analysis.
Flow Logs: Log information about IP traffic flowing to and from network interfaces in your Azure Virtual Network.

Learn more about Network Watcher capabilities.

Azure Firewall and Network Security Group (NSG) Logs

Both Azure Firewall and NSGs generate detailed logs that can be sent to Azure Monitor Logs (Log Analytics) or Azure Storage for analysis. These logs provide insights into allowed and denied traffic, aiding in security audits and troubleshooting.

Example log query for denied traffic in NSG:

AzureDiagnostics
| where ResourceProvider == "MICROSOFT.NETWORK" and Category == "NetworkSecurityGroupFlowEvent"
| where FlowStatus == "Deny"
| project TimeGenerated, ResourceId, SourceIP, DestinationIP, DestinationPort, Protocol, NetworkInterfaceName, RuleName, FlowStatus

Advanced Monitoring Techniques

Beyond the core services, several advanced techniques can provide deeper insights and automation for your Azure network monitoring.

Traffic Analytics

Traffic Analytics (part of Network Watcher) processes Network Security Group flow logs to provide rich visualizations and insights into network traffic flow patterns in your Azure environment. It helps you understand traffic distribution, identify top talkers, and detect anomalies.

Key features of Traffic Analytics include:

Visualizing traffic flow by IP address, application, protocol, and port.
Identifying top conversations and communication patterns.
Detecting high-bandwidth flows and potential security risks.
Integrating with Microsoft Sentinel for threat detection.

Azure Monitor Agent and Data Collection Rules

For more granular control over data collection, especially from VMs and hybrid environments, consider using the Azure Monitor Agent (AMA) and Data Collection Rules (DCRs). DCRs allow you to specify which logs and metrics to collect from which sources and send them to Log Analytics workspaces or other destinations.

Custom Metrics and Log Queries

Leverage Azure Monitor's powerful Kusto Query Language (KQL) to write custom queries against your network logs. This allows you to extract specific information, create custom dashboards, and build tailored alerts that meet your unique monitoring requirements.

Note: Regularly review and refine your monitoring configurations to ensure they align with evolving network architecture and security policies.

Best Practices for Azure Network Monitoring

Implementing a robust monitoring strategy involves adhering to best practices.

Centralize Logs: Use a dedicated Log Analytics workspace to centralize logs from all your networking resources.
Define Baselines: Establish performance baselines for key network metrics to easily identify deviations.
Configure Meaningful Alerts: Set up alerts for critical events and performance degradations, but avoid alert fatigue by tuning them carefully.
Regularly Review Traffic: Use Traffic Analytics and flow logs to periodically review traffic patterns and security posture.
Automate Responses: Integrate monitoring with automation tools (e.g., Azure Logic Apps, Azure Functions) to automatically respond to certain alerts.
Document Your Setup: Maintain clear documentation of your monitoring architecture, alert rules, and diagnostic procedures.