Merge pull request #219185 from aimee-littleton/patch-110

SNAT alert update

Author: prmerger-automator[bot]

articles/virtual-network/nat-gateway/nat-metrics.md

@@ -252,6 +252,8 @@ To create the alert, use the following steps:
 
 8. From the When to evaluate section, select **1 minute** under the **Check every** drop-down menu.
 
+9. For the lookback period, select **5 minutes** from the drop-down menu options. 
+
 9. Create an **Action** for your alert by providing a name, notification type, and type of action that is performed when the alert is triggered.
 
 10. Before deploying your action, **test the action group**.
@@ -296,4 +298,4 @@ For more information on what each metric is showing you and how to analyze these
 * 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)
-* Learn about [troubleshooting NAT gateway resources](troubleshoot-nat.md).
+* Learn about [troubleshooting NAT gateway resources](troubleshoot-nat.md).