added note about elb ip change

Author: seligj95

articles/app-service/environment/how-to-migrate.md

@@ -88,6 +88,10 @@ If the step is in progress, you get a status of `Migrating`. After you get a sta
 az rest --method get --uri "${ASE_ID}/configurations/networking?api-version=2021-02-01"
 ```
 
+> [!NOTE]
+> Due to a known bug, for ELB App Service Environment migrations, the inbound IP address may change again once the [migration step](#migrate-to-app-service-environment-v3) is complete. Be prepared to update your dependent resources again with the new inbound IP address after the migration step is complete. This bug is being addressed and will be fixed as soon as possible. Open a support case if you have any questions or concerns about this issue or need help with the migration process.
+>
+
 ## 4. Update dependent resources with new IPs
 
 By using the new IPs, update any of your resources or networking components to ensure that your new environment functions as intended after migration is complete. It's your responsibility to make any necessary updates.
@@ -223,6 +227,10 @@ Get the details of your new environment by running the following command or by g
 az appservice ase show --name $ASE_NAME --resource-group $ASE_RG
 ```
 
+> [!NOTE]
+> Due to a known bug, for ELB App Service Environment migrations, the inbound IP address may change once the [migration step](#migrate-to-app-service-environment-v3) is complete. Check your App Service Environment v3's IP addresses and make any needed updates if there have been changes since the IP generation step. Open a support case if you have any questions or concerns about this issue or need help with the confirming the new IPs.
+>
+
 ::: zone-end
 
 ::: zone pivot="experience-azp"
@@ -321,6 +329,10 @@ At this time, detailed migration statuses are available only when you're using t
 
 When migration is complete, you have an App Service Environment v3 resource, and all of your apps are running in your new environment. You can confirm the environment's version by checking the **Configuration** page for your App Service Environment.
 
+> [!NOTE]
+> Due to a known bug, for ELB App Service Environment migrations, the inbound IP address may change once the [migration step](#migrate-to-app-service-environment-v3) is complete. Check your App Service Environment v3's IP addresses and make any needed updates if there have been changes since the IP generation step. Open a support case if you have any questions or concerns about this issue or need help with the confirming the new IPs.
+>
+
 If your migration includes a custom domain suffix, the domain appeared in the **Essentials** section of the **Overview** page of the portal for App Service Environment v1/v2, but it no longer appears there in App Service Environment v3. Instead, for App Service Environment v3, go to the **Custom domain suffix** page to confirm that your custom domain suffix is configured correctly. You can also remove the configuration if you no longer need it or configure one if you didn't have one previously.
 
 :::image type="content" source="./media/migration/custom-domain-suffix-app-service-environment-v3.png" alt-text="Screenshot that shows the page for custom domain suffix configuration for App Service Environment v3.":::

articles/app-service/environment/how-to-side-by-side-migrate.md

@@ -4,7 +4,7 @@ description: Learn how to migrate your App Service Environment v2 to App Service
 author: seligj95
 ms.topic: tutorial
 ms.custom: devx-track-azurecli
-ms.date: 4/9/2024
+ms.date: 4/12/2024
 ms.author: jordanselig
 ---
 # Use the side-by-side migration feature to migrate App Service Environment v2 to App Service Environment v3
@@ -256,7 +256,7 @@ az rest --method get --uri "${ASE_ID}?api-version=2022-03-01" --query properties
 
 ## 11. Redirect customer traffic, validate your App Service Environment v3, and complete migration
 
-This step is your opportunity to test and validate your new App Service Environment v3. Your App Service Environment v2 front ends are still running, but the backing compute is an App Service Environment v3. If you're able to access your apps without issues that means you're ready to complete the migration. If you want to test your App Service Environment v3 front ends, you can do so by using the inbound IP address you got in the previous step.
+This step is your opportunity to test and validate your new App Service Environment v3. Your App Service Environment v2 front ends are still running, but the backing compute is an App Service Environment v3. TODO: If you're able to access your apps without issues that means you're ready to complete the migration. If you want to test your App Service Environment v3 front ends, you can do so by using the inbound IP address you got in the previous step.
 
 Once you confirm your apps are working as expected, you can redirect customer traffic to your new App Service Environment v3 by running the following command. This command also deletes your old environment.
 

articles/app-service/environment/migrate.md

@@ -113,6 +113,10 @@ When completed, you'll be given the new IPs that your future App Service Environ
 
 Once the new IPs are created, you have the new default outbound to the internet public addresses. In preparation for the migration, you can adjust any external firewalls, DNS routing, network security groups, and any other resources that rely on these IPs. For ELB App Service Environment, you also have the new inbound IP address that you can use to set up new endpoints with services like [Traffic Manager](../../traffic-manager/traffic-manager-overview.md) or [Azure Front Door](../../frontdoor/front-door-overview.md). **It's your responsibility to update any and all resources that will be impacted by the IP address change associated with the new App Service Environment v3. Don't move on to the next step until you've made all required updates.** This step is also a good time to review the [inbound and outbound network](networking.md#ports-and-network-restrictions) dependency changes when moving to App Service Environment v3 including the port change for the Azure Load Balancer health probe, which now uses port 80.
 
+> [!IMPORTANT]
+> Due to a known bug, for ELB App Service Environment migrations, the inbound IP address may change again once the [migration step](#migrate-to-app-service-environment-v3) is complete. Be prepared to update your dependent resources again with the new inbound IP address after the migration step is complete. This bug is being addressed and will be fixed as soon as possible. Open a support case if you have any questions or concerns about this issue or need help with the migration process.
+>
+
 ### Delegate your App Service Environment subnet
 
 App Service Environment v3 requires the subnet it's in to have a single delegation of `Microsoft.Web/hostingEnvironments`. Migration can't succeed if the App Service Environment's subnet isn't delegated or you delegate it to a different resource.

articles/app-service/environment/side-by-side-migrate.md

@@ -3,7 +3,7 @@ title: Migrate to App Service Environment v3 by using the side-by-side migration
 description: Overview of the side-by-side migration feature for migration to App Service Environment v3.
 author: seligj95
 ms.topic: article
-ms.date: 4/8/2024
+ms.date: 4/12/2024
 ms.author: jordanselig
 ms.custom: references_regions
 ---
@@ -202,7 +202,7 @@ The new inbound IP address is given so that you can set up new endpoints with se
 
 ### Redirect customer traffic, validate your App Service Environment v3, and complete migration
 
-The final step is to redirect traffic to your new App Service Environment v3 and complete the migration. The platform does this change for you, but only when you initiate it. Before you do this step, you should review your new App Service Environment v3 and perform any needed testing to validate that it's functioning as intended. Your App Service Environment v2 front ends are still running, but the backing compute is an App Service Environment v3. If you're using an ILB App Service Environment v3, you can test your App Service Environment v3 front ends by updating your private DNS zones with the new inbound IP address. Testing this change allows you to fully validate your App Service Environment v3 before initiating the final step of the migration where your old App Service Environment is deleted.
+The final step is to redirect traffic to your new App Service Environment v3 and complete the migration. The platform does this change for you, but only when you initiate it. Before you do this step, you should review your new App Service Environment v3 and perform any needed testing to validate that it's functioning as intended. Your App Service Environment v2 front ends are still running, but the backing compute is an App Service Environment v3. If you're using an ILB App Service Environment v3, you can test your App Service Environment v3 front ends by updating your private DNS zones with the new inbound IP address. If you're using an ELB App Service Environment v3,...TODO: Testing this change allows you to fully validate your App Service Environment v3 before initiating the final step of the migration where your old App Service Environment is deleted.
 
 Once you're ready to redirect traffic, you can complete the final step of the migration. This step updates internal DNS records to point to the load balancer IP address of your new App Service Environment v3 and the front ends that were created during the migration. Changes are effective within a couple minutes. If you run into issues, check your cache and TTL settings. This step also shuts down your old App Service Environment and deletes it. Your new App Service Environment v3 is now your production environment.