Merge pull request #224261 from craigshoemaker/aca/subnet-updates

[Container Apps] Subnet updates

Author: prmerger-automator[bot]

articles/container-apps/disaster-recovery.md

@@ -6,7 +6,7 @@ author: craigshoemaker
 ms.author: cshoe
 ms.service: container-apps
 ms.topic: tutorial
-ms.date: 6/17/2022
+ms.date: 1/18/2023
 ---
 
 # Disaster recovery guidance for Azure Container Apps
@@ -33,10 +33,10 @@ Additionally, the following resources can help you create your own disaster reco
 
 ## Set up zone redundancy in your Container Apps environment
 
-To take advantage of availability zones, you must enable zone redundancy when you create the Container Apps environment.  The environment must include a virtual network (VNET) with an infrastructure subnet.  To ensure proper distribution of replicas, you should configure your app's minimum and maximum replica count with values that are divisible by three.  The minimum replica count should be at least three. 
+To take advantage of availability zones, you must enable zone redundancy when you create the Container Apps environment.  The environment must include a virtual network (VNET) with an available subnet.  To ensure proper distribution of replicas, you should configure your app's minimum and maximum replica count with values that are divisible by three.  The minimum replica count should be at least three.
+
+### Enable zone redundancy via the Azure portal
 
-### Enable zone redundancy via the Azure portal 
- 
 To create a container app in an environment with zone redundancy enabled using the Azure portal:
 
 1. Navigate to the Azure portal.
@@ -62,6 +62,9 @@ Create a VNET and infrastructure subnet to include with the Container Apps envir
 
 When using these commands, replace the `<PLACEHOLDERS>` with your values.
 
+>[!NOTE]
+> The subnet associated with a Container App Environment requires a CIDR prefix of `/23` or larger.
+
 # [Bash](#tab/bash)
 
 ```azurecli

articles/container-apps/firewall-integration.md

@@ -22,6 +22,9 @@ Using custom user-defined routes (UDRs) or ExpressRoutes, other than with UDRs o
 
 The following tables describe how to configure a collection of NSG allow rules.
 
+>[!NOTE]
+> The subnet associated with a Container App Environment requires a CIDR prefix of `/23` or larger.
+
 ### Inbound
 
 | Protocol | Port | ServiceTag | Description |

articles/container-apps/networking.md

@@ -153,7 +153,7 @@ The second URL grants access to the log streaming service and the console. If ne
 ## Ports and IP addresses
 
 >[!NOTE]
-> The subnet associated with a Container App Environment requires a CIDR prefix of /21 or larger (/20, /19 etc.).
+> The subnet associated with a Container App Environment requires a CIDR prefix of `/23` or larger.
 
 The following ports are exposed for inbound connections.
 

articles/container-apps/vnet-custom-internal.md

@@ -75,7 +75,7 @@ $VnetName = 'my-custom-vnet'
 Now create an instance of the virtual network to associate with the Container Apps environment. The virtual network must have two subnets available for the container app instance.
 
 > [!NOTE]
-> You can use an existing virtual network, but a dedicated subnet with a CIDR range of `/21` or larger is required for use with Container Apps.
+> You can use an existing virtual network, but a dedicated subnet with a CIDR range of `/23` or larger is required for use with Container Apps.
 
 # [Bash](#tab/bash)
 
@@ -119,7 +119,7 @@ $vnet = New-AzVirtualNetwork @VnetArgs
 ---
 
 > [!NOTE]
-> Network subnet address prefix requires a CIDR range of `/21`.
+> Network subnet address prefix requires a minimum CIDR range of `/23`.
 
 With the VNET established, you can now query for the infrastructure subnet ID.
 

articles/container-apps/vnet-custom.md

@@ -21,7 +21,7 @@ The following example shows you how to create a Container Apps environment in an
 [!INCLUDE [container-apps-create-portal-steps.md](../../includes/container-apps-create-portal-steps.md)]
 
 > [!NOTE]
-> Network address prefixes requires a CIDR range of `/21` or larger (`/20`, `/19` etc.).
+> Network address prefixes requires a CIDR range of `/23` or larger.
 
 7. Select the **Networking** tab to create a VNET.
 8. Select **Yes** next to *Use your own virtual network*.
@@ -94,7 +94,7 @@ $VnetName = 'my-custom-vnet'
 Now create an Azure virtual network to associate with the Container Apps environment. The virtual network must have a subnet available for the environment deployment.
 
 > [!NOTE]
-> You can use an existing virtual network, but a dedicated subnet with a CIDR range of `/21` or larger is required for use with Container Apps.
+> You can use an existing virtual network, but a dedicated subnet with a CIDR range of `/23` or larger is required for use with Container Apps.
 
 # [Bash](#tab/bash)
 
@@ -336,7 +336,7 @@ You must either provide values for all three of these properties, or none of the
 
 | Parameter | Description |
 |---|---|
-| `VnetConfigurationPlatformReservedCidr` | The address range used internally for environment infrastructure services. Must have a size between `/21` and `/12`. |
+| `VnetConfigurationPlatformReservedCidr` | The address range used internally for environment infrastructure services. Must have a size between `/23` and `/12`. |
 | `VnetConfigurationPlatformReservedDnsIP` | An IP address from the `VnetConfigurationPlatformReservedCidr` range that is used for the internal DNS server. The address can't be the first address in the range, or the network address. For example, if `VnetConfigurationPlatformReservedCidr` is set to `10.2.0.0/16`, then `VnetConfigurationPlatformReservedDnsIP` can't be `10.2.0.0` (the network address), or `10.2.0.1` (infrastructure reserves use of this IP). In this case, the first usable IP for the DNS would be `10.2.0.2`. |
 | `VnetConfigurationDockerBridgeCidr` | The address range assigned to the Docker bridge network. This range must have a size between `/28` and `/12`. |