6.1.1.7 Ensure that virtual network flow logs are captured and sent to Log Analytics

Information

Ensure that virtual network flow logs are captured and fed into a central log analytics workspace.

Virtual network flow logs provide critical visibility into traffic patterns. Sending logs to a Log Analytics workspace enables centralized analysis, correlation, and alerting for faster threat detection and response.

NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.

Solution

Remediate from Azure Portal

- Go to Network Watcher.
- Under Logs, click Flow logs.
- Click + Create.
- Select a subscription.
- Next to Flow log type, select Virtual network.
- Click + Select target resource.
- Select Virtual network.
- Select a virtual network.
- Click Confirm selection.
- Select a storage account, or create a new storage account.
- Set the retention in days for the storage account.
- Click Next.
- Under Analytics, for Flow logs version, select Version 2.
- Check the box next to Enable traffic analytics.
- Select a processing interval.
- Select a Log Analytics Workspace.
- Click Next.
- Optionally, add Tags.
- Click Review + create.
- Click Create.
- Repeat steps 1-20 for each subscription or virtual network requiring remediation.

Impact:

- Virtual network flow logs are charged per gigabyte of network flow logs collected and come with a free tier of 5 GB/month per subscription.
- If traffic analytics is enabled with virtual network flow logs, traffic analytics pricing applies at per gigabyte processing rates.
- The storage of logs is charged separately.

See Also

https://workbench.cisecurity.org/benchmarks/21611

Item Details

Category: SYSTEM AND INFORMATION INTEGRITY

References: 800-53|SI-4, 800-53|SI-4(4), CSCv7|12.8

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