Merge pull request #175212 from noakup/master

Adding a note on the minimum subnet range

Author: PRMerger19

articles/azure-monitor/logs/private-link-design.md

@@ -165,6 +165,11 @@ We've identified the following products and experiences query workspaces through
 > * Container Insights
 
 ## Requirements
+
+### Network subnet size
+The smallest supported IPv4 subnet is /27 (using CIDR subnet definitions). While Azure VNets [can be as small as /29](../../virtual-network/virtual-networks-faq.md#how-small-and-how-large-can-vnets-and-subnets-be), Azure [reserves 5 IP addresses](../../virtual-network/virtual-networks-faq.md#are-there-any-restrictions-on-using-ip-addresses-within-these-subnets) and the Azure Monitor Private Link setup requires at least 11 additional IP addresses, even if connecting to a single workspace. [Review your endpoint's DNS settings](./private-link-configure.md#reviewing-your-endpoints-dns-settings) for the detailed list of Azure Monitor Private Link endpoints.
+
+
 ### Agents
 The latest versions of the Windows and Linux agents must be used to support secure ingestion to Log Analytics workspaces. Older versions can't upload monitoring data over a private network.