Merge pull request #116651 from erichrt/patch-12

Add Health Probe IP Question

Author: PRMerger15

articles/load-balancer/load-balancer-faqs.md

@@ -27,5 +27,8 @@ See the [list of Azure Load Balancer quickstart templates](https://docs.microsof
 ## How are inbound NAT rules different from load-balancing rules?
 NAT rules are used to specify a backend resource to route traffic to. For example, configuring a specific load balancer port to send RDP traffic to a specific VM. Load-balancing rules are used to specify a pool of backend resources to route traffic to, balancing the load across each instance. For example, a load balancer rule can route TCP packets on port 80 of the load balancer across a pool of web servers.
 
+## What is IP 168.63.129.16?
+The virtual IP address for the host tagged as the Azure infrastructure Load Balancer where the Azure Health Probes originate. When configuring backend instances, they must allow traffic from this IP address to successfully respond to health probes. This rule does not interact with access to your Load Balancer frontend. If you're not using the Azure Load Balancer, you can override this rule. You can learn more about service tags [here](https://docs.microsoft.com/azure/virtual-network/service-tags-overview#available-service-tags).
+
 ## Next Steps
 If your question is not listed above, please send feedback about this page with your question. This will create a GitHub issue for the product team to ensure all of our valued customer questions are answered.