Merge pull request #279741 from madsd/subnetsize

Alter text on subnet size

Author: prmerger-automator[bot]

articles/app-service/overview-vnet-integration.md

@@ -70,9 +70,9 @@ The virtual network integration feature supports two virtual interfaces per work
 
 Virtual network integration depends on a dedicated subnet. When you create a subnet, the Azure subnet consumes five IPs from the start. One address is used from the integration subnet for each App Service plan instance. If you scale your app to four instances, then four addresses are used.
 
-When you scale up/down in instance size, the amount of IP addresses used by the App Service plan is temporarily doubled while the scale operation completes. The new instances need to be fully operational before the existing instances are deprovisioned. The scale operation affects the real, available supported instances for a given subnet size. Platform upgrades need free IP addresses to ensure upgrades can happen without interruptions to outbound traffic. Finally, after scale up, down, or in operations complete, there might be a short period of time before IP addresses are released. In rare cases, this operation can be up to 12 hours.
+When you scale up/down in instance size, the amount of IP addresses used by the App Service plan is temporarily doubled while the scale operation completes. The new instances need to be fully operational before the existing instances are deprovisioned. The scale operation affects the real, available supported instances for a given subnet size. Platform upgrades need free IP addresses to ensure upgrades can happen without interruptions to outbound traffic. Finally, after scale up, down, or in operations complete, there might be a short period of time before IP addresses are released. In rare cases, this operation can be up to 12 hours and if you rapidly scaling in/out or up/down, you need more IPs than the maximum scale.
 
-Because subnet size can't be changed after assignment, use a subnet that's large enough to accommodate whatever scale your app might reach. You should also reserve IP addresses for platform upgrades. To avoid any issues with subnet capacity, use a `/26` with 64 addresses. When you're creating subnets in Azure portal as part of integrating with the virtual network, a minimum size of `/27` is required. If the subnet already exists before integrating through the portal, you can use a `/28` subnet.
+Because subnet size can't be changed after assignment, use a subnet that's large enough to accommodate whatever scale your app might reach. You should also reserve IP addresses for platform upgrades. To avoid any issues with subnet capacity, we recommand allocating double the IPs of your planned maximum scale. A `/26` with 64 addresses cover the maximum scale of a single multitenant App Service plan. When you're creating subnets in Azure portal as part of integrating with the virtual network, a minimum size of `/27` is required. If the subnet already exists before integrating through the portal, you can use a `/28` subnet.
 
 With multi plan subnet join (MPSJ), you can join multiple App Service plans in to the same subnet. All App Service plans must be in the same subscription but the virtual network/subnet can be in a different subscription. Each instance from each App Service plan requires an IP address from the subnet and to use MPSJ a minimum size of `/26` subnet is required. If you plan to join many and/or large scale plans, you should plan for larger subnet ranges.