Merge pull request #265856 from kengaderdus/help-after-custom-domain

Help users to know how to block default B2C domain after activating a custom domain.

Author: prmerger-automator[bot]

articles/active-directory-b2c/custom-domain.md

@@ -1,12 +1,12 @@
 ---
-title: Enable Azure AD B2C custom domains
+title: Enable custom domains in Azure Active Directory B2C
 titleSuffix: Azure AD B2C
-description: Learn how to enable custom domains in your redirect URLs for Azure Active Directory B2C.
+description: Learn how to enable custom domains in your redirect URLs for Azure Active Directory B2C, so that my users have a seamless experience. 
 author: kengaderdus
 manager: CelesteDG
 ms.service: active-directory
 ms.topic: how-to
-ms.date: 01/26/2024
+ms.date: 02/14/2024
 ms.author: kengaderdus
 ms.subservice: B2C
 ms.custom: "b2c-support"
@@ -15,7 +15,7 @@ zone_pivot_groups: b2c-policy-type
 #Customer intent: As a developer, I want to use my own domain name for the sign-in and sign-up experience, so that my users have a seamless experience.
 ---
 
-# Enable custom domains for Azure Active Directory B2C
+# Enable custom domains in Azure Active Directory B2C
 
 [!INCLUDE [active-directory-b2c-choose-user-flow-or-custom-policy](../../includes/active-directory-b2c-choose-user-flow-or-custom-policy.md)]
 
@@ -52,8 +52,12 @@ When using custom domains, consider the following:
 
 - You can set up multiple custom domains. For the maximum number of supported custom domains, see [Microsoft Entra service limits and restrictions](/entra/identity/users/directory-service-limits-restrictions) for Azure AD B2C and [Azure subscription and service limits, quotas, and constraints](/azure/azure-resource-manager/management/azure-subscription-service-limits#azure-front-door-classic-limits) for Azure Front Door.
 - Azure Front Door is a separate Azure service, so extra charges will be incurred. For more information, see [Front Door pricing](https://azure.microsoft.com/pricing/details/frontdoor).
-- After you configure custom domains, users will still be able to access the Azure AD B2C default domain name *<tenant-name>.b2clogin.com* (unless you're using a custom policy and you [block access](#optional-block-access-to-the-default-domain-name).
-- If you have multiple applications, migrate them all to the custom domain because the browser stores the Azure AD B2C session under the domain name currently being used.
+- If you've multiple applications, migrate all oft them to the custom domain because the browser stores the Azure AD B2C session under the domain name currently being used.
+- After you configure custom domains, users will still be able to access the Azure AD B2C default domain name *<tenant-name>.b2clogin.com*. You need to block access to the default domain so that attackers can't use it to access your apps or run distributed denial-of-service (DDoS) attacks. [Submit a support ticket](find-help-open-support-ticket.md) to request for the  blocking of access to the default domain.
+
+> [!WARNING]
+> Don't request blocking of the default domain until your custom domain works properly.
+
 
 ## Prerequisites