diff --git a/sdk/apimanagement/arm-apimanagement/src/models/index.ts b/sdk/apimanagement/arm-apimanagement/src/models/index.ts
index f91afeb3611d..f18a2f5c10f4 100644
--- a/sdk/apimanagement/arm-apimanagement/src/models/index.ts
+++ b/sdk/apimanagement/arm-apimanagement/src/models/index.ts
@@ -2355,13 +2355,22 @@ export interface ApiManagementServiceBaseProperties {
    */
   additionalLocations?: AdditionalLocation[];
   /**
-   * Custom properties of the API Management service. Setting
+   * Custom properties of the API Management service.</br>Setting
    * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Ciphers.TripleDes168` will disable the
-   * cipher TLS_RSA_WITH_3DES_EDE_CBC_SHA for all TLS(1.0, 1.1 and 1.2). Setting
+   * cipher TLS_RSA_WITH_3DES_EDE_CBC_SHA for all TLS(1.0, 1.1 and 1.2).</br>Setting
    * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Protocols.Tls11` can be used to disable
-   * just TLS 1.1 and setting
+   * just TLS 1.1.</br>Setting
    * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Protocols.Tls10` can be used to disable
-   * TLS 1.0 on an API Management service.
+   * TLS 1.0 on an API Management service.</br>Setting
+   * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Backend.Protocols.Tls11` can be used to
+   * disable just TLS 1.1 for communications with backends.</br>Setting
+   * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Backend.Protocols.Tls10` can be used to
+   * disable TLS 1.0 for communications with backends.</br>Setting
+   * `Microsoft.WindowsAzure.ApiManagement.Gateway.Protocols.Server.Http2` can be used to enable
+   * HTTP2 protocol on an API Management service.</br>Not specifying any of these properties on
+   * PATCH operation will reset omitted properties' values to their defaults. For all the settings
+   * except Http2 the default value is `True` if the service was created on or before April 1st
+   * 2018 and `False` otherwise. Http2 setting's default value is `False`.
    */
   customProperties?: { [propertyName: string]: string };
   /**
@@ -2505,13 +2514,22 @@ export interface ApiManagementServiceResource extends ApimResource {
    */
   additionalLocations?: AdditionalLocation[];
   /**
-   * Custom properties of the API Management service. Setting
+   * Custom properties of the API Management service.</br>Setting
    * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Ciphers.TripleDes168` will disable the
-   * cipher TLS_RSA_WITH_3DES_EDE_CBC_SHA for all TLS(1.0, 1.1 and 1.2). Setting
+   * cipher TLS_RSA_WITH_3DES_EDE_CBC_SHA for all TLS(1.0, 1.1 and 1.2).</br>Setting
    * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Protocols.Tls11` can be used to disable
-   * just TLS 1.1 and setting
+   * just TLS 1.1.</br>Setting
    * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Protocols.Tls10` can be used to disable
-   * TLS 1.0 on an API Management service.
+   * TLS 1.0 on an API Management service.</br>Setting
+   * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Backend.Protocols.Tls11` can be used to
+   * disable just TLS 1.1 for communications with backends.</br>Setting
+   * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Backend.Protocols.Tls10` can be used to
+   * disable TLS 1.0 for communications with backends.</br>Setting
+   * `Microsoft.WindowsAzure.ApiManagement.Gateway.Protocols.Server.Http2` can be used to enable
+   * HTTP2 protocol on an API Management service.</br>Not specifying any of these properties on
+   * PATCH operation will reset omitted properties' values to their defaults. For all the settings
+   * except Http2 the default value is `True` if the service was created on or before April 1st
+   * 2018 and `False` otherwise. Http2 setting's default value is `False`.
    */
   customProperties?: { [propertyName: string]: string };
   /**
@@ -2639,13 +2657,22 @@ export interface ApiManagementServiceUpdateParameters extends ApimResource {
    */
   additionalLocations?: AdditionalLocation[];
   /**
-   * Custom properties of the API Management service. Setting
+   * Custom properties of the API Management service.</br>Setting
    * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Ciphers.TripleDes168` will disable the
-   * cipher TLS_RSA_WITH_3DES_EDE_CBC_SHA for all TLS(1.0, 1.1 and 1.2). Setting
+   * cipher TLS_RSA_WITH_3DES_EDE_CBC_SHA for all TLS(1.0, 1.1 and 1.2).</br>Setting
    * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Protocols.Tls11` can be used to disable
-   * just TLS 1.1 and setting
+   * just TLS 1.1.</br>Setting
    * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Protocols.Tls10` can be used to disable
-   * TLS 1.0 on an API Management service.
+   * TLS 1.0 on an API Management service.</br>Setting
+   * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Backend.Protocols.Tls11` can be used to
+   * disable just TLS 1.1 for communications with backends.</br>Setting
+   * `Microsoft.WindowsAzure.ApiManagement.Gateway.Security.Backend.Protocols.Tls10` can be used to
+   * disable TLS 1.0 for communications with backends.</br>Setting
+   * `Microsoft.WindowsAzure.ApiManagement.Gateway.Protocols.Server.Http2` can be used to enable
+   * HTTP2 protocol on an API Management service.</br>Not specifying any of these properties on
+   * PATCH operation will reset omitted properties' values to their defaults. For all the settings
+   * except Http2 the default value is `True` if the service was created on or before April 1st
+   * 2018 and `False` otherwise. Http2 setting's default value is `False`.
    */
   customProperties?: { [propertyName: string]: string };
   /**