Added number of required IPs

Author: RoseHJM

articles/dev-box/concept-dev-box-deployment-guide.md

@@ -108,6 +108,8 @@ When you have the following requirements, you need to use Azure network connecti
 
 When connecting to resources on-premises through Microsoft Entra hybrid joins, work with your Azure network topology expert. Best practice is to implement a [hub-and-spoke network topology](/azure/cloud-adoption-framework/ready/azure-best-practices/hub-spoke-network-topology). The hub is the central point that connects to your on-premises network; you can use an Express Route, a site-to-site VPN, or a point-to-site VPN. The spoke is the virtual network that contains the dev boxes. You peer the dev box virtual network to the on-premises connected virtual network to provide access to on-premises resources. Hub and spoke topology can help you manage network traffic and security.
 
+Network planning should include an estimate of the number of IP addresses you'll need, and their distribution across VNETs. Additional free IP addresses are necessary for the Azure Network connection health check. If the health check fails the dev box definition will not update. You need 1 additional IP address per dev box, and two IP addresses for the health check and Dev Box infrastructure.
+
 Learn more about [Microsoft Dev Box networking requirements](./concept-dev-box-network-requirements.md?tabs=W365).
 
 ### Step 3: Configure security groups for role-based access control

articles/dev-box/concept-dev-box-network-requirements.md

@@ -229,6 +229,8 @@ These FQDNs and endpoints only correspond to client sites and resources. This li
 
 ## Troubleshooting 
 
+This section covers some common connect and network issues.
+
 ### Connection issues
 
 - **Logon attempt failed**
@@ -243,7 +245,6 @@ These FQDNs and endpoints only correspond to client sites and resources. This li
 
   For more information about troubleshooting group policy issues, see [Applying Group Policy troubleshooting guidance](/troubleshoot/windows-server/group-policy/applying-group-policy-troubleshooting-guidance).
 
-
 ### IPv6 addressing issues
 
 If you're experiencing IPv6 issues, check that the *Microsoft.AzureActiveDirectory* service endpoint is not enabled on the virtual network or subnet. This service endpoint converts the IPv4 to IPv6.
@@ -252,11 +253,10 @@ For more information, see [Virtual Network service endpoints](/azure/virtual-net
 
 ### Updating dev box definition image issues
 
-When you update the image used in a dev box definition, you must ensure that you have sufficient IP addresses available in your virtual network.
+When you update the image used in a dev box definition, you must ensure that you have sufficient IP addresses available in your virtual network. Additional free IP addresses are necessary for the Azure Network connection health check. If the health check fails the dev box definition will not update. You need 1 additional IP address per dev box, and two IP addresses for the health check and Dev Box infrastructure.
 
 For more information about updating dev box definition images, see [Update a dev box definition](how-to-manage-dev-box-definitions.md#update-a-dev-box-definition).
 
-
 ## Related content
 
 - [Check access to required FQDNs and endpoints for Azure Virtual Desktop](/azure/virtual-desktop/check-access-validate-required-fqdn-endpoint).

articles/dev-box/how-to-manage-dev-box-definitions.md

@@ -96,7 +96,7 @@ The following steps show you how to create a dev box definition by using an exis
 
 Over time, your needs for dev boxes can change. You might want to move from a Windows 10 base operating system to a Windows 11 base operating system, or increase the default compute specification for your dev boxes. Your initial dev box definitions might no longer be appropriate for your needs. You can update a dev box definition so new dev boxes use the new configuration.
 
-When you update the image used in a dev box definition, you must ensure that you have sufficient IP addresses available in your virtual network.
+When you update the image used in a dev box definition, you must ensure that you have sufficient IP addresses available in your virtual network. Additional free IP addresses are necessary for the Azure Network connection health check. If the health check fails the dev box definition will not update. You need 1 additional IP address per dev box, and two IP addresses for the health check and Dev Box infrastructure.
 
 You can update the image, image version, compute, and storage settings for a dev box definition: