Determine destinations to which traffic is being sent from Azure VM

Below steps to build-up a dashboard or alert for unusual outbound traffic.

 

1. Enable Azure Network Watcher

• Go to Azure Portal > Network Watcher.
• Ensure it’s enabled for the region where your VM is deployed.

This enables tools like:

• NSG Flow Logs: Shows outbound connections from the VM.
• Packet Capture: Captures traffic at the NIC level.
• Connection Monitor: Tracks connectivity between endpoints.

 

2. Enable NSG Flow Logs

• Go to Network Security Group (NSG) attached to your VM.
• Under Diagnostics, enable Flow Logs.
• Store logs in a Storage Account or send to Log Analytics.

Flow logs show:

• Source IP and port
• Destination IP and port
• Protocol and direction
• Whether traffic was allowed or denied

You can analyze these logs using:

• Azure Monitor Logs (KQL)
• Traffic Analytics

 

4. Use On-VM Tools for Immediate Insight

If you have access to the VM:

Windows:

netstat -n | findstr ESTABLISHED

Linux:

ss -tunap

 

These show:

• Active outbound connections
• Destination IPs and ports
• Associated processes

 

5. Use Azure Monitor + Log Analytics

• Enable Diagnostics on the VM and NIC.
• Send logs to Log Analytics workspace.
• KQL queries:

AzureNetworkAnalytics_CL
| where Direction_s == "Outbound"
| summarize count() by DestinationIP_s

Azure Network Watcher overview | Microsoft Learn