Description:
Network Security Group Flow Logs should be enabled and the retention period is set to greater than or equal to 90 days.
Rationale:
Flow logs enable capturing information about IP traffic flowing in and out of network security groups. Logs can be used to check for anomalies and give insight into suspected breaches.
This will keep IP traffic logs for longer than 90 days. As a level 2, first determine your need to retain data, then apply your selection here. As this is data stored for longer, your monthly storage costs will increase depending on your data use.
From Azure Console
Using Azure Command Line Interface 2.0
Enable the 'NSG flow logs' and set the Retention (days) to greater than or equal to 90 days.
az network watcher flow-log configure --nsg --enabled true --resource-group --retention 91 --storage-account
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