Merge pull request #106313 from christiankuhtz/patch-288

init

Author: megvanhuygen

articles/virtual-network/nat-metrics.md

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+---
+title: Metrics and alerts for Azure Virtual Network NAT 
+titleSuffix: Azure Monitor metrics and alerts for Azure Virtual Network NAT
+description: Understand Azure Monitor metrics and alerts available for Virtual Network NAT.
+services: virtual-network
+documentationcenter: na
+author: asudbring
+manager: KumudD
+ms.service: virtual-network
+Customer intent: As an IT administrator, I want to understand available Azure Monitor metrics and alerts for Virtual Network NAT.
+ms.devlang: na
+ms.topic: overview
+ms.tgt_pltfrm: na
+ms.workload: infrastructure-services
+ms.date: 03/03/2020
+ms.author: allensu
+---
+
+# Azure Virtual Network NAT metrics
+
+Azure Virtual Network NAT gateway resources provide multi-dimensional metrics. You can use these metrics to observe the operation and for [troubleshooting](nat-metrics.md).  Alerts can be configured for critical issues such as SNAT exhaustion.
+
+<p align="center">
+  <img src="media/nat-overview/flow-direction1.svg" width="256" title="Virtual Network NAT for outbound to Internet">
+</p>
+
+*Figure: Virtual Network NAT for outbound to Internet*
+
+>[!NOTE] 
+>Virtual Network NAT is available as public preview at this time. Currently it's only available in a limited set of [regions](nat-overview.md#region-availability). This preview is provided without a service level agreement and isn't recommended for production workloads. Certain features may not be supported or may have constrained capabilities. See the [Supplemental Terms of Use for Microsoft Azure Previews](https://azure.microsoft.com/support/legal/preview-supplemental-terms) for details.
+
+## Metrics
+
+NAT gateway resources provide the following multi-dimensional metrics in Azure Monitor:
+
+| Metric | Description | Recommended Aggregation | Dimensions |
+|---|---|---|---|
+| Bytes | Bytes processed inbound and outbound | Sum | Direction (In; Out), Protocol (6 TCP; 17 UDP) |
+| Packets | Packets processed inbound and outbound | Sum | Direction (In; Out), Protocol (6 TCP; 17 UDP) |
+| Dropped packets | Packets dropped by the NAT gateway | Sum | / |
+| SNAT Connection Count | State transitions per interval | Sum | Connection State, Protocol (6 TCP; 17 UDP) |
+| Total SNAT connection count | Current active SNAT connections (~ SNAT ports in use) | Sum | Protocol (6 TCP; 17 UDP) |
+
+
+## Alerts
+
+Alerts for metrics can be configured in Azure Monitor for each of the preceding [metrics](#metrics).
+
+## Limitations
+
+Resource Health isn't supported.
+
+## Next steps
+
+- Learn about [Virtual Network NAT](nat-overview.md)
+- Learn about [NAT gateway resource](nat-gateway-resource.md)
+- Learn about [Azure Monitor](../azure-monitor/overview.md)