---
title: "Always On Client Connectivity (SQL Server) | Microsoft Docs"
ms.custom: ""
ms.date: "04/27/2017"
ms.prod: "sql-server-2014"
ms.reviewer: ""
ms.technology: high-availability
ms.topic: conceptual
helpviewer_keywords: 
  - "Availability Groups [SQL Server], listeners"
  - "Availability Groups [SQL Server], prerequisites and restrictions"
  - "Availability Groups [SQL Server], client connectivity"
ms.assetid: b456448d-1757-48c8-8bbb-2d1c2d6d61e9
author: MashaMSFT
ms.author: mathoma
manager: craigg
---
# Always On Client Connectivity (SQL Server)
  This topic describes considerations for client connectivity to AlwaysOn Availability Groups, including prerequisites, restrictions, and recommendations for client configurations and settings.  
  
 
  
##  <a name="ClientConnSupport"></a> Client Connectivity Support  
 The section below provides information about [!INCLUDE[ssHADR](../../../includes/sshadr-md.md)] support for client connectivity.  
  
 **Driver Support**  
  
 The following table summarizes driver support for [!INCLUDE[ssHADR](../../../includes/sshadr-md.md)]:  
  
|Driver|Multi-Subnet Failover|Application Intent|Read-Only Routing|Multi-Subnet Failover: Faster Single Subnet Endpoint Failover|Multi-Subnet Failover: Named Instance Resolution For SQL Clustered Instances|  
|------------|----------------------------|------------------------|------------------------|--------------------------------------------------------------------|-----------------------------------------------------------------------------------|  
|SQL Native Client 11.0 ODBC|Yes|Yes|Yes|Yes|Yes|  
|SQL Native Client 11.0 OLEDB|No|Yes|Yes|No|No|  
|ADO.NET with .NET Framework 4.0 with connectivity patch**<sup>*</sup>** |Yes|Yes|Yes|Yes|Yes|  
|ADO.NET with .NET Framework 3.5 SP1 with connectivity patch **<sup>**</sup>** |Yes|Yes|Yes|Yes|Yes|  
|Microsoft JDBC driver 4.0 for SQL Server|Yes|Yes|Yes|Yes|Yes|  
  
 **<sup>*</sup>**  Download the connectivity patch for ADO .NET with .NET Framework 4.0: [https://support.microsoft.com/kb/2600211](https://support.microsoft.com/kb/2600211).  
  
 **<sup>**</sup>**  Download the connectivity patch for ADO.NET with .NET Framework 3.5 SP1: [https://support.microsoft.com/kb/2654347](https://support.microsoft.com/kb/2654347).  
  
> [!IMPORTANT]  
>  To connect to an availability group listener, a client must use a TCP connection string.  
  
##  <a name="RelatedTasks"></a> Related Tasks  
  
-   [Creation and Configuration of Availability Groups &#40;SQL Server&#41;](creation-and-configuration-of-availability-groups-sql-server.md)  
  
-   [Create or Configure an Availability Group Listener &#40;SQL Server&#41;](create-or-configure-an-availability-group-listener-sql-server.md)  
  

  
## See Also  
 [Overview of AlwaysOn Availability Groups &#40;SQL Server&#41;](overview-of-always-on-availability-groups-sql-server.md)   
 [Failover Clustering and AlwaysOn Availability Groups &#40;SQL Server&#41;](failover-clustering-and-always-on-availability-groups-sql-server.md)   
 [Prerequisites, Restrictions, and Recommendations for AlwaysOn Availability Groups &#40;SQL Server&#41;](prereqs-restrictions-recommendations-always-on-availability.md)   
 [Availability Group Listeners, Client Connectivity, and Application Failover &#40;SQL Server&#41;](../../listeners-client-connectivity-application-failover.md)   
 [About Client Connection Access to Availability Replicas &#40;SQL Server&#41;](about-client-connection-access-to-availability-replicas-sql-server.md)   
 [Microsoft SQL Server AlwaysOn Solutions Guide for High Availability and Disaster Recovery](https://go.microsoft.com/fwlink/?LinkId=227600)   
 [SQL Server AlwaysOn Team Blog: The official SQL Server AlwaysOn Team Blog](https://blogs.msdn.com/b/sqlalwayson/)   
 [A long time delay occurs when you reconnect an IPSec connection from a computer that is running Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, or Windows Server 2008 R2](https://support.microsoft.com/kb/980915)   
 [The Cluster service takes about 30 seconds to fail over IPv6 IP addresses in Windows Server 2008 R2](https://support.microsoft.com/kb/2578113)   
 [Slow failover operation if no router exists between the cluster and an application server](https://support.microsoft.com/kb/2582281)