Always On VPN Options for Azure Deployments

Always On VPN Options for Azure DeploymentsOrganizations everywhere are rapidly adopting Microsoft Azure public cloud infrastructure to extend or replace their existing datacenter. As traditional on-premises workloads are migrated to the cloud, customers are looking for options to host VPN services there as well.

Windows Server

Windows Server with the Routing and Remote Access Service (RRAS) installed is a popular choice for on-premises Always On VPN deployments. Intuitively it would make sense to deploy Windows Server and RRAS in Azure as well. However, at the time of this writing, RRAS is not a supported workload on Windows Server in Azure.

Always On VPN Options for Azure Deployments

Reference: https://support.microsoft.com/en-us/help/2721672/microsoft-server-software-support-for-microsoft-azure-virtual-machines/

Although explicitly unsupported, it is possible to deploy Windows Server and RRAS in Azure for Always On VPN. In my experience it works well and can be an option for organizations willing to forgo formal support by Microsoft.

Azure Gateway

Options for supporting Always On VPN connections using native Azure VPN infrastructure depend on the type of VPN gateway chosen.

VPN Gateway

The Azure VPN Gateway can be configured to support client-based (point-to-site) VPN. With some additional configuration it can be used to support Windows 10 Always On VPN deployments. Azure VPN gateway supports either IKEv2 or SSTP VPN protocols for client connections. The Azure VPN gateway has some limitations though. Consider the following:

  • A route-based VPN gateway is required
  • A maximum of 1000 concurrent IKEv2 connections are supported when using the VpnGw3 or VpnGw3AZ SKUs (2000 supported in active/active mode)
  • A maximum of 128 concurrent SSTP connections are supported on all gateway SKUs (256 supported in active/active mode)
  • The gateway can be configured to support either device or user connections, not both.

Virtual WAN

Azure Virtual WAN is the future of remote connectivity for Azure. It includes support for client-based VPN (currently in public preview at the time of this writing), but only supports IKEv2 and OpenVPN VPN protocols for client connections. SSTP is not supported at all. Further, OpenVPN is not supported for Windows 10 Always On VPN, leaving IKEv2 as the only option, which poses some potential operational challenges. Virtual WAN offer much better scalability though, supporting up to 10,000 concurrent client-based VPN connections. Like the Azure VPN gateway, Azure Virtual WAN can be configured to support either device or user connections, not both.

Virtual Appliance

The most supportable option for hosting VPN services in Azure for Windows 10 Always On VPN is to deploy a third-party Network Virtual Appliance (NVA). They are available from a variety of vendors including Cisco, Check Point, Palo Alto Networks, Fortinet, and many others. To support Windows 10 Always On VPN, the NVA vendor must either support IKEv2 for client-based VPN connections or have a Universal Windows Platform (UWP) VPN plug-in client available from the Microsoft store. Click here to learn more about Always On VPN and third-party VPN devices.

Note: Be careful when choosing an NVA as some vendors support IKEv2 only for site-to-site VPN, but not client-based VPN!

Hybrid Deployments

For organizations with hybrid cloud deployments (infrastructure hosted on-premises and in Azure), there are several options for choosing the best location to deploy VPN services. In general, it is recommended that client VPN connections be established nearest the resources accessed by remote clients. However, having VPN servers hosted both on-premises and in Azure is fully supported. In this scenario Azure Traffic Manager can be configured to intelligently route VPN connections for remote clients.

NetMotion Mobility

The NetMotion Mobility purpose-built enterprise VPN is a popular replacement for Microsoft DirectAccess. It is also an excellent alternative for enterprise organizations considering a migration to Always On VPN. It is a software-based solution that can be deployed on Windows Server and is fully supported running in Microsoft Azure. It offers many advanced features and capabilities not included in other remote access solutions.

Summary

Administrators have many options for deploying VPN servers in Azure to support Windows 10 Always On VPN. Windows Server and RRAS is the simplest and most cost-effective option, but it is not formally supported by Microsoft. Azure VPN gateway is an interesting alternative but lacks enough capacity for larger deployments. Azure Virtual WAN is another option but has limited protocol support. Deploying an NVA is a good choice, and NetMotion Mobility is an excellent alternative to both DirectAccess and Always On VPN that is software-based and fully supported in Azure.

Additional Information

Windows 10 Always On VPN with Azure Gateway

Windows 10 Always On VPN and Third-Party VPN Devices

Windows 10 Always On VPN and Windows Server Routing and Remote Access Service (RRAS)

Windows 10 Always On VPN IKEv2 Features and Limitations

Windows 10 Always On VPN Multisite with Azure Traffic Manager

Comparing DirectAccess and NetMotion Mobility

Deploying NetMotion Mobility in Microsoft Azure

Always On VPN and Third Party VPN Devices

Always On VPN and Third Party VPN DevicesOne of the most important advantages Windows 10 Always On VPN has over DirectAccess is infrastructure independence. That is, Always On VPN does not rely exclusively on a Windows Server infrastructure to support Always On VPN connections. Always On VPN will work with many third-party firewalls and VPN devices, as long as they meet some basic requirements.

Advantages

Third-party firewalls or VPN devices offer some important advantages over Windows Servers running the Routing and Remote Access Services (RRAS), both in terms of security and performance.

Security

Dedicated security devices (physical or virtual) provide better security than a common Windows server. They commonly run specialized, security-hardened operating systems that are highly secure and resistant to attack. In addition, these solutions typically allow the administrator to define policy to restrict access to internal resources and do so in a centralized way. This is often easier to implement and manage than using traffic filters on the client side. They often include advanced security features such as URL filtering and malware inspection to better protect remote clients. Some solutions include Hardware Security Module (HSM) integration to further enhance security.

Performance

Purpose-built solutions often provide better throughput and performance than do Windows Servers by virtue of their proprietary operating systems. This allows for better network throughput and the ability to support many more connections per device.

Disadvantages

The main drawbacks for using a third-party device are cost and administrative overhead. Third-party solutions must be acquired, for which there is typically a non-trivial cost associated. They often need additional per-user licensing. In addition, many of these solutions require specialized skill sets to implement, manage, and support which could further increase the overall cost of the solution.

Interoperability Requirements

Any firewall or VPN device can be used for Always On VPN as long as they support the Internet Key Exchange version 2 (IKEv2) VPN protocol for remote access connections. Most modern firewalls today support IKEv2, but some (such as the Sophos XG firewall) do not. Check with your vendor to validate support.

Native Client

If the firewall or VPN device supports IKEv2 for remote access connections, the native Windows VPN provider can be used to establish an Always On VPN connection. The native provider is used when the Always On VPN ProfileXML is configured using the NativeProfile element.

Plug-In VPN Client

One crucial drawback to using IKEv2 is that it is commonly blocked by firewalls. Many third-party VPN vendors offer a plug-in client that enables support for TLS-based transport, which is more firewall friendly than IKEv2. Plug-in VPN providers are available in the Microsoft store.

Below is a current list of available third-party VPN plug-in providers for Windows 10. (Updated April 5 to now include Cisco AnyConnect!)

  • Check Point Capsule
  • Cisco AnyConnect
  • F5 Access
  • Fortinet Forticlient
  • Palo Alto GlobalProtect
  • Pulse Secure
  • SonicWall Mobile Connect

Always On VPN and Third-Party VPN Devices

Note: Win32 VPN client applications from third-party vendors are not supported with Windows 10 Always On VPN.

Additional Information

What is the Difference Between DirectAccess and Always On VPN?

5 Things DirectAccess Administrators Should Know about Always On VPN

3 Important Advantages of Always On VPN over DirectAccess

3 Important Advantages of Always On VPN over DirectAccess

3 Important Advantages of Always On VPN over DirectAccess Windows 10 Always On VPN hands-on training classes now forming. Details here.

Windows 10 Always On VPN provides seamless and transparent, always on remote network access similar to DirectAccess. The mechanics of how it is delivered and managed are fundamentally different, as I discussed here. Some of these changes will no doubt present challenges to our way of thinking, especially in the terms of client provisioning. However, Always On VPN brings along with it some important and significant advantages too.

No More NLS

A Network Location Server (NLS) is used for inside/outside detection by DirectAccess clients. By design, the NLS is reachable by DirectAccess machines only when they are on the internal network. NLS availability is crucial. If the NLS is offline or unreachable for any reason at all, DirectAccess clients on the internal network will mistakenly believe they are outside the network. In this scenario, the client will attempt to establish a DirectAccess connection even though it is inside. This often fails, leaving the DirectAccess client in a state where it cannot connect to any internal resources by name until the NLS is brought back online.

Always On VPN eliminates the frailty of NLS by using the DNS connection suffix for trusted network detection. When a network connection is established, an Always On VPN connection will not be established if the DNS connection suffix matches what the administrator has defined as the internal trusted network.

Full Support for IPv4

DirectAccess uses IPv6 exclusively for communication between remote DirectAccess clients and the DirectAccess server. IPv6 translation technologies allow for communication to internal IPv4 hosts. While this works for the vast majority of scenarios, there are still many challenges with applications that do not support IPv6.

Always On VPN supports both IPv4 and IPv6, so application incompatibility issues will be a thing of the past! With full support for IPv4, the need for IPv6 transition and translation technologies is eliminated. This reduces protocol overhead and improves network performance.

Infrastructure Independent

3 Important Advantages of Always On VPN over DirectAccess Windows servers are required to implement DirectAccess. Always On VPN can be implemented using Windows servers as well, but it isn’t a hard requirement. Always On VPN is implemented entirely on the Windows 10 client, which means any third-party VPN device can be used on the back end, including Cisco, Checkpoint, Juniper, Palo Alto, Fortinet, SonicWALL, F5, strongSwan, and others! This provides tremendous deployment flexibility, making it possible to mix and match backend infrastructure if required. For example, a Windows RRAS VPN server with Palo Alto and SonicWALL firewalls could all be implemented at the same time (using the Windows built-in VPN client). Importantly, making changes to VPN infrastructure is much less impactful and disruptive to clients in the field. VPN devices can be upgraded, replaced, and moved internally without requiring corresponding policy changes on the client.

Additional Information

Always On VPN and the Future of Microsoft DirectAccess 

5 Things DirectAccess Administrators Should Know about Always On VPN 

Contact Me

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