Azure Firewall active instances

Question

Azure Firewall active instances

Christian80 0

Hello,

I've an Azure Fw Standard SKU, I know that can scale up to 20 instances. I would like to know if I can monitor the active instances

Thanks

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Answer 1

Alex Burlachenko 9,780

Hi Christian,

3 ways to you can easily monitor your Azure Firewall's active instances

1 Quick Portal Check. Go to your Azure Firewall resource under Monitoring -> Metrics Select "Firewall Health Status" View "Instance Count"

2 Using PowerShell

# Connect to Azure first (if not already connected)
Connect-AzAccount

# Get firewall instance count
$firewall = Get-AzFirewall -Name "Your-Firewall-Name" -ResourceGroupName "Your-RG"
$metrics = Get-AzMetric -ResourceId $firewall.Id -MetricName "FirewallHealth" -TimeGrain 00:01:00

# Display current instance count
$latest = $metrics.Data | Sort-Object -Property Timestamp -Descending | Select-Object -First 1
Write-Output "Active instances: $($latest.FirewallInstanceCount)"

Azure CLI Option

az monitor metrics list

Your Standard SKU auto-scales (2-20 instances). High counts usually mean heavy traffic. Data updates every 1-5 minutes.

Best regards,

Alex

P.S. If my answer help to you, please Accept my answer

Ganesh Patapati 6,915 Reputation points Microsoft External Staff Moderator

2025-03-25T11:22:55.08+00:00
Hello Christian80

In addition to Alex Burlachenko provided answer, I just want to add few more details:

You can also enable Diagnostic Settings on your azure firewall to collect logs for traffic and scaling events. These logs can be analyzed in Azure Log Analytics for detailed insights.

To capture instance-specific details, select Log Categories as below.

AzureFirewallApplicationRule

AzureFirewallNetworkRule

AzureFirewallDnsProxy then look for the instanceId field in logs to track which instance processed a request. You can use below query to count active instances and returns the number of distinct instances processing traffic.

AzureDiagnostics

| where ResourceType == "AZUREFIREWALLS"

| summarize count() by instanceId

| count

If you find that this answers your question, kindly click Upvote it so other people with the same question can find the answer.
Ganesh Patapati 6,915 Reputation points Microsoft External Staff Moderator

2025-03-27T13:42:30.57+00:00

Hello Christian80

Following up to see if the above suggestion was helpful. And, if you have any further query do let us know.

If above is unclear and/or you are unsure about something add a comment below.

Please "Accept the answer" if the information helped you. This will help us and others in the community as well.
Ganesh Patapati 6,915 Reputation points Microsoft External Staff Moderator

2025-03-31T14:19:53.63+00:00

Hello Christian80

Following up to see if the above suggestion was helpful. And, if you have any further query do let us know.

If above is unclear and/or you are unsure about something add a comment below.

Please "Upvote" and "Accept the answer" if the information helped you. This will help us and others in the community as well.

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Azure Firewall active instances

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