DirectAccess Troubleshooting and the Windows 10 Network Connectivity Assistant

DirectAccess Troubleshooting and the Windows 10 Network Connectivity AssistantOne of the first places administrators look for information about the DirectAccess client connection is the Network Connectivity Assistant (NCA). The NCA is used to view current connection status and to gather detailed information that is helpful for troubleshooting failed DirectAccess connections. The NCA was first integrated with the client operating system beginning with Windows 8. Similar functionality can be extended to Windows 7 clients by installing and configuring the Windows 7 DirectAccess Connectivity Assistant (DCA).

NCA

The DirectAccess NCA can be accessed by pressing the Windows Key + I and then clicking on Network & Internet and DirectAccess. Here you’ll find a helpful visual indicator of current connectivity status, and for multisite deployments you’ll also find details about the current entry point.

DirectAccess Troubleshooting and the Windows 10 Network Connectivity Assistant

DirectAccess Missing?

If DirectAccess does not appear in the list, open an elevated PowerShell window and restart the Network Connectivity Assistant service (NcaSvc) using the following command.

Restart-Service NcaSvc

If you receive the error “Failed to start service ‘Network Connectivity Assistant (NcaSvc)‘”, ensure that the client operating system is Enterprise or Education edition. The NCA service will always fail to start on Professional edition as it is not a supported DirectAccess client.

Log Collection

The DirectAccess NCA also provides access to crucial troubleshooting information. Clicking on the Collect button creates a detailed diagnostic log file that is often helpful for troubleshooting DirectAccess connectivity issues.

DirectAccess Troubleshooting and the Windows 10 Network Connectivity Assistant

Troubleshooting Info Missing?

The option to collect a log, and email it to your IT admin will only be displayed if a support email address is defined in the DirectAccess configuration. To define a support email address, open the Remote Access Management console and perform the following steps.

1. Click Edit on Step 1.
2. Click Network Connectivity Assistant.
3. Enter an email address in the Helpdesk email address field.
4. Click Finish to complete Step 1.
5. Click Finish to apply the changes.

Email Program

Microsoft assumes that an end user will be generating the DirectAccess client troubleshooting log and will be emailing them to their administrator. If an email program is not installed on the client, the following information is displayed.

There is no email program associated to perform the requested action. Please install an email program or, if one is already installed, create an associate in the Default Programs control panel.

DirectAccess Troubleshooting and the Windows 10 Network Connectivity Assistant

If you wish to simply view the log file on the client and not email them, you can find the generated DirectAccess troubleshooting log file in HTML format in the following location.

%SystemDrive%\Users\%Username%\AppData\Local\Temp

DirectAccess Troubleshooting and the Windows 10 Network Connectivity Assistant

Unable to Generate Log Files

There are numerous reports that generating the DirectAccess troubleshooting log fails on Windows 10 v1709. DirectAccess administrators have been reporting that the process seems to fail during the creation of the log file, leaving it truncated and incomplete. To resolve this issue, open an elevated PowerShell window and enter the following command.

New-ItemProperty -Path “HKLM:\SYSTEM\CurrentControlSet\Services\NcaSvc\” -Name SvcHostSplitDisable -PropertyType DWORD -Value 1 -Force

The computer must be restarted for this change to take effect. If initial testing of this workaround is successful, the registry setting can be pushed out to all DirectAccess clients using Active Directory Group Policy Preferences.

Additional Information

Installing and Configuring DirectAccess Connectivity Assistant 2.0 on Windows 7 Clients

Planning and Implementing DirectAccess with Windows Server 2016 Video Training Course on Pluralsight

Managing and Supporting DirectAccess with Windows Server 2016 Video Training Course on Pluralsight

Implementing DirectAccess with Windows Server 2016 Book

DirectAccess IP-HTTPS Performance Issues

DirectAccess IP-HTTPS Performance IssuesPerformance issues with DirectAccess are not uncommon. In fact, there are numerous threads on Microsoft and third-party forums where administrators frequently complain about slow download speeds, especially when using the IP-HTTPS IPv6 transition technology. Based on my experience the problem does not appear to be widespread but occurs with enough regularity that it is worthy of further investigation.

DirectAccess Design

The inherent design of DirectAccess is a major limiting factor for performance. DirectAccess uses a complex and heavy communication channel, with multiple layers of encapsulation, encryption, and translation. Fundamentally it is IPsec encrypted IPv6 traffic, encapsulated in HTTP, and then encrypted with Transport Layer Security (TLS) and routed over IPv4. It is then decrypted, decapsulated, decrypted again, then converted back to IPv4. The high protocol overhead incurred with multiple layers of encapsulation, encryption, and translation result in increased packet fragmentation, which further reduces performance.

DirectAccess Performance

Even under the best circumstances, DirectAccess performance is limited by many other factors, most notably the quality of the network connection between the client and the server. DirectAccess performs reasonably well over high bandwidth, low latency connections. However, network performance drops precipitously as latency increases and packet loss is encountered. This is to be expected given the design of the solution.

Intermediary Devices

It is not uncommon to find intermediary devices like firewalls, intrusion detection systems, malware scanners, and other security inspection devices limit the performance of DirectAccess clients. In addition, many security appliances have bandwidth caps enforced in software for licensing restrictions. Further, incorrect configuration of inline edge devices can contribute to increased fragmentation, which leads to poor performance as well.

Slow Downloads over IP-HTTPS

Many people report that download speeds seem to be artificially capped at 355Kbps. While this seems to be a display bug in the UI, there is plenty of evidence to indicate that, in some scenarios, DirectAccess is incapable of high throughput even over high-quality connections. Some who have deployed DirectAccess and VPN on the same server have reported that download speeds are only limited when using DirectAccess over IP-HTTPS and not with VPN using Secure Socket Tunneling Protocol (SSTP), which also uses TLS. This has led many to speculate that the issue is either a bug or a design flaw in the IP-HTTPS tunnel interface itself.

TCP Window Scaling Issues

In some of the network traces I’ve analyzed I’ve seen evidence that seems to support this theory. For example, a network trace taken when downloading a file over DirectAccess with IP-HTTPS showed the TCP window never scaled beyond 64K, which would seriously impede performance. Interestingly this doesn’t seem to happy when the client uploads files over IP-HTTPS. Clearly something unusual is happening.

Microsoft KB Article

Microsoft recently released a vaguely-worded KB article that appears to lend credence to some of these findings. The article seems to acknowledge the fact there are known issues with DirectAccess performance, but it lacks any specific details as to what the root cause is. Instead, it simply advises migrating to Windows 10 Always On VPN.

Summary

DirectAccess IP-HTTPS performance issues don’t appear to affect everyone, and the problem only seems to apply to file downloads and not to other types of traffic. However, there is mounting evidence of a systemic issue with DirectAccess performance especially over IP-HTTPS. Customers are advised to closely evaluate their uses cases for DirectAccess and if remote clients are frequently required to download large files over a DirectAccess connection, an alternative method of file transfer might be required. Optionally customers can consider evaluating alternative remote access solutions that offer better performance such as Windows 10 Always On VPN or third-party solutions such as NetMotion Mobility.

Additional Resources

Always On VPN and the Future of DirectAccess

What’s the Difference Between DirectAccess and Always On VPN?

NetMotion Mobility as an Alternative to Microsoft DirectAccess

What is the Difference Between DirectAccess and Always On VPN?

Always On VPN Device Tunnel Configuration Guidance Now AvailableDirectAccess has been around for many years, and with Microsoft now moving in the direction of Always On VPN, I’m often asked “What’s the difference between DirectAccess and Always On VPN?” Fundamentally they both provide seamless and transparent, always on remote access. However, Always On VPN has a number of advantages over DirectAccess in terms of security, authentication and management, performance, and supportability.

Security

DirectAccess provides full network connectivity when a client is connected remotely. It lacks any native features to control access on a granular basis. It is possible to restrict access to internal resources by placing a firewall between the DirectAccess server and the LAN, but the policy would apply to all connected clients.

Windows 10 Always On VPN includes support for granular traffic filtering. Where DirectAccess provides access to all internal resources when connected, Always On VPN allows administrators to restrict client access to internal resources in a variety of ways. In addition, traffic filter policies can be applied on a per-user or group basis. For example, users in accounting can be granted access only to their department servers. The same could be done for HR, finance, IT, and others.

Authentication and Management

DirectAccess includes support for strong user authentication with smart cards and one-time password (OTP) solutions. However, there is no provision to grant access based on device configuration or health, as that feature was removed in Windows Server 2016 and Windows 10. In addition, DirectAccess requires that clients and servers be joined to a domain, as all configuration settings are managed using Active Directory group policy.

Windows 10 Always On VPN includes support for modern authentication and management, which results in better overall security. Always On VPN clients can be joined to an Azure Active Directory and conditional access can also be enabled. Modern authentication support using Azure MFA and Windows Hello for Business is also supported. Always On VPN is managed using Mobile Device Management (MDM) solutions such as Microsoft Intune.

Performance

DirectAccess uses IPsec with IPv6, which must be encapsulated in TLS to be routed over the public IPv4 Internet. IPv6 traffic is then translated to IPv4 on the DirectAccess server. DirectAccess performance is often acceptable when clients have reliable, high quality Internet connections. However, if connection quality is fair to poor, the high protocol overhead of DirectAccess with its multiple layers of encapsulation and translation often yields poor performance.

The protocol of choice for Windows 10 Always On VPN deployments is IKEv2. It offers the best security and performance when compared to TLS-based protocols. In addition, Always On VPN does not rely exclusively on IPv6 as DirectAccess does. This reduces the many layers of encapsulation and eliminates the need for complex IPv6 transition and translation technologies, further improving performance over DirectAccess.

Supportability

DirectAccess is a Microsoft-proprietary solution that must be deployed using Windows Server and Active Directory. It also requires a Network Location Server (NLS) for clients to determine if they are inside or outside the network. NLS availability is crucial and ensuring that it is always reachable by internal clients can pose challenges, especially in very large organizations.

Windows 10 Always On VPN supporting infrastructure is much less complex than DirectAccess. There’s no requirement for a NLS, which means fewer servers to provision, manage, and monitor. In addition, Always On VPN is completely infrastructure independent and can be deployed using third-party VPN servers such as Cisco, Checkpoint, SonicWALL, Palo Alto, and more.

Summary

Windows 10 Always On VPN is the way of the future. It provides better overall security than DirectAccess, it performs better, and it is easier to manage and support.

Here’s a quick summary of some important aspects of VPN, DirectAccess, and Windows 10 Always On VPN.

Traditional VPN DirectAccess Always On VPN
Seamless and Transparent No Yes Yes
Automatic Connection Options None Always on Always on, app triggered
Protocol Support IPv4 and IPv6 IPv6 Only IPv4 and IPv6
Traffic Filtering No No Yes
Azure AD Integration No No Yes
Modern Management Yes No (group policy only) Yes (MDM)
Clients must be domain-joined? No Yes No
Requires Microsoft Infrastructure No Yes No
Supports Windows 7 Yes Yes Windows 10 only

Always On VPN Hands-On Training

If you are interested in learning more about Windows 10 Always On VPN, consider registering for one of my hands-on training classes. More details here.

Additional Resources

Always On VPN and the Future of Microsoft DirectAccess

5 Important Things DirectAccess Administrators Should Know about Windows 10 Always On VPN

3 Important Advantages of Windows 10 Always On VPN over DirectAccess

DirectAccess IP-HTTPS Null Cipher Suites Not Available

DirectAccess IP-HTTPS Null Cipher Suites Not AvailableMicrosoft first introduced support for null cipher suites for the IP-HTTPS IPv6 transition technology in Windows Server 2012, and it is supported for DirectAccess in Windows 8.x and Windows 10 clients. Using null cipher suites for IP-HTTPS eliminates the needless double encryption that occurs when using encrypted cipher suites. DirectAccess is a unique workload where SSL/TLS encryption isn’t really required because the payload being transported in HTTPS is already encrypted.

No Encryption by Design

When supporting Windows 8.x and Windows 10 clients, ensuring null cipher suites (TLS_RSA_WITH_NULL_SHA and TLS_RSA_WITH_NULL_SHA256) are enabled and operational is crucial to providing the highest levels of performance and scalability for the remote access solution. When following implementation best practices, this isn’t really an issue. However, in some cases null cipher suites may be disabled. This will result in reduced scalability and degraded performance for Windows 8.x and Windows 10 clients.

Validating SSL/TLS Configuration

The easiest way to verify that null cipher suites are being offered by the DirectAccess server is to use the Qualys SSL Labs server test site. Ideally you should see a result similar to this.

DirectAccess IP-HTTPS Null Cipher Suites Not AvailableFigure 1. Qualys SSL Labs server test site results for properly configured DirectAccess server.

Don’t be alarmed by the overall rating “F”. That happens because the Qualys test site is designed to test web servers where using null cipher suites would be a serious security issue. As I stated previously, the DirectAccess workload is unique in that its HTTPS payload is already encrypted, so using null cipher suites is acceptable in this scenario.

DirectAccess IP-HTTPS Null Cipher Suites Not AvailableFigure 2. Qualys SSL Labs server test site results for properly configured DirectAccess server showing support for null SSL/TLS cipher suites.

Null Cipher Suites Missing

When performing the Qualys SSL labs server test on a DirectAccess server, an overall rating of “A” is not desirable and indicates the DirectAccess server is misconfigured. This is caused by the lack of support for null cipher suites.

DirectAccess IP-HTTPS Null Cipher Suites Not AvailableFigure 3. Qualys SSL Labs server test site results for misconfigured DirectAccess server.

Common Causes

Null cipher suites for SSL and TLS can be disabled for a variety of reasons. Below are some of the most common causes for the lack of support for null cipher suites for DirectAccess.

Self-Signed Certificates – Using the Getting Started Wizard (simplified deployment) will configure DirectAccess using a self-signed certificate for IP-HTTPS. Using a self-signed certificate is discouraged for numerous reasons, most importantly because it disables support for null cipher suites.

Security Hardening – Security administrators may proactively disable support for null cipher suites in a misguided effort to “improve security” for DirectAccess. While this is acceptable and recommended on a web server, it is not advisable to disable null cipher suites on a DirectAccess server.

SSL Certificate Signing Algorithm – Using an SSL certificate signed with an Elliptical Curve (EC) key as opposed to an RSA key will result in the loss of support for null cipher suites for IP-HTTPS. High security/assurance certificates signed with EC keys are not recommended for use on DirectAccess servers and should be avoided if possible.

DirectAccess Configuration Options – Enabling One-Time Password (OTP) authentication on the DirectAccess server will also result in a loss of support for null cipher suites. Also, adding additional roles to the DirectAccess server such as client-based VPN or the Web Application Proxy (WAP) can also result in null cipher suites being disabled.

Summary

Null cipher suites are implemented by design on DirectAccess servers to enhance performance for Windows 8.x and Windows 10 clients and improve overall scalability for the implementation. They eliminate the pointless double encryption of DirectAccess communication, which itself is already encrypted. For optimal performance and scalability, be sure to follow implementation best practices and use a PKI-managed (public or private) SSL certificate signed with an RSA key (SHA-256 recommended). Resist the urge to “harden” the DirectAccess server by disabling support for null cipher suites, and avoid the use of SSL certificates signed with EC keys. In addition, carefully consider DirectAccess deployment options such as OTP authentication and consider deploying roles such as VPN and WAP on a separate server.

Additional Information

DirectAccess IP-HTTPS SSL and TLS Insecure Cipher Suites

DirectAccess IP-HTTPS Null Encryption and SSTP VPN

DirectAccess and FIPS Compliant Algorithms for Encryption

SSL Certificate Considerations for DirectAccess IP-HTTPS 

 

 

DirectAccess Manage Out with ISATAP and NLB Clustering

DirectAccess Manage Out with ISATAP and NLB ClusteringDirectAccess connections are bidirectional, allowing administrators to remotely connect to clients and manage them when they are out of the office. DirectAccess clients use IPv6 exclusively, so any communication initiated from the internal network to remote DirectAccess clients must also use IPv6. If IPv6 is not deployed natively on the internal network, the Intrasite Automatic Tunnel Addressing Protocol (ISATAP) IPv6 transition technology can be used to enable manage out.

ISATAP Supportability

According to Microsoft’s support guidelines for DirectAccess, using ISATAP for manage out is only supported for single server deployments. ISATAP is not supported when deployed in a multisite or load-balanced environment.

Not supported” is not the same as “doesn’t work” though. For example, ISATAP can easily be deployed in single site DirectAccess deployments where load balancing is provided using Network Load Balancing (NLB).

ISATAP Configuration

To do this, you must first create DNS A resource records for the internal IPv4 address for each DirectAccess server as well as the internal virtual IP address (VIP) assigned to the cluster.

DirectAccess Manage Out with ISATAP and NLB Clustering

Note: Do NOT use the name ISATAP. This name is included in the DNS query block list on most DNS servers and will not resolve unless it is removed. Removing it is not recommended either, as it will result in ALL IPv6-enabled hosts on the network configuring an ISATAP tunnel adapter.

Once the DNS records have been added, you can configure a single computer for manage out by opening an elevated PowerShell command window and running the following command:

Set-NetIsatapConfiguration -State Enabled -Router [ISATAP FQDN] -PassThru

DirectAccess Manage Out with ISATAP and NLB Clustering

Once complete, an ISATAP tunnel adapter network interface with a unicast IPv6 address will appear in the output of ipconfig.exe, as shown here.

DirectAccess Manage Out with ISATAP and NLB Clustering

Running the Get-NetRoute -AddressFamily IPv6 PowerShell command will show routes to the client IPv6 prefixes assigned to each DirectAccess server.

DirectAccess Manage Out with ISATAP and NLB Clustering

Finally, verify network connectivity from the manage out host to the remote DirectAccess client.

Note: There is a known issue with some versions of Windows 10 and Windows Server 2016 that may prevent manage out using ISATAP from working correctly. There’s a simple workaround, however. More details can be found here.

Group Policy Deployment

If you have more than a few systems on which to enable ISATAP manage out, using Active Directory Group Policy Objects (GPOs) to distribute these settings is a much better idea. You can find guidance for creating GPOs for ISATAP manage out here.

DirectAccess Client Firewall Configuration

Simply enabling ISATAP on a server or workstation isn’t all that’s required to perform remote management on DirectAccess clients. The Windows firewall running on the DirectAccess client computer must also be configured to securely allow remote administration traffic from the internal network. Guidance for configuring the Windows firewall on DirectAccess clients for ISATAP manage out can be found here.

ISATAP Manage Out for Multisite and ELB

The configuration guidance in this post will not work if DirectAccess multisite is enabled or external load balancers (ELB) are used. However, ISATAP can still be used. For more information about enabling ISATAP manage out with external load balancers and/or multisite deployments, fill out the form below and I’ll provide you with more details.

Summary

Once ISATAP is enabled for manage out, administrators on the internal network can remotely manage DirectAccess clients wherever they happen to be. Native Windows remote administration tools such as Remote Desktop, Windows Remote Assistance, and the Computer Management MMC can be used to manage remote DirectAccess clients. In addition, enterprise administration tools such as PowerShell remoting and System Center Configuration Manger (SCCM) Remote Control can also be used. Further, third-party remote administration tools such as VNC, TeamViewer, LogMeIn, GoToMyPC, Bomgar, and many others will also work with DirectAccess ISATAP manage out.

Additional Information

ISATAP Recommendations for DirectAccess Deployments

DirectAccess Manage Out with ISATAP Fails on Windows 10 and Windows Server 2016 

DirectAccess Client Firewall Rule Configuration for ISATAP Manage Out

DirectAccess Manage Out and System Center Configuration Manager (SCCM)

Contact Me

Interested in learning more about ISATAP manage out for multisite and external load balancer deployments? Fill out the form below and I’ll get in touch with you.

DirectAccess and FIPS Compliant Algorithms for Encryption

DirectAccess administrators may be required to enable Federal Information Processing Standards (FIPS) compliant algorithms for encryption, hashing, and signing on DirectAccess servers to meet certain regulatory and compliance requirements.

DirectAccess and FIPS Compliant Algorithms for Encryption

Performance Impact

Be advised that enabling this setting will disable support for null cipher suites for the IP-HTTPS IPv6 transition technology. This will result in the double encryption of all DirectAccess client communication, which will increase resource consumption on DirectAccess servers. This leads to reduced scalability and degraded performance for all DirectAccess clients, including Windows 8.x and Windows 10.

If enabling FIPS compliant cannot be avoided, additional compute capacity (CPU and memory) should be provisioned. For best results, add additional servers to distribute the workload and improve performance for DirectAccess clients.

Always On VPN

If you’re looking for better security and performance, consider migrating to Windows 10 Always On VPN. Always On VPN fully supports FIPS compliant algorithms without the negative performance impact associated with DirectAccess. If you’d like to learn more about security and Always On VPN, fill out the form below and I’ll get in touch with you.

Additional Resources

Always On VPN and the Future of DirectAccess 

5 Things DirectAccess Administrators Should Know About Always On VPN 

3 Important Advantages of Always On VPN over DirectAccess 

SSL Certificate Considerations for DirectAccess IP-HTTPS

SSL Certificate Considerations for DirectAccess IP-HTTPSDirectAccess uses IPv6 exclusively for communication between the client and server. IPv6 transition technologies are used to support DirectAccess communication over the IPv4 public Internet. One of those IPv6 transition technologies, IP-HTTPS, uses HTTP for encapsulation and SSL/TLS for authentication of the DirectAccess server.

SSL Certificates

When configuring DirectAccess, an SSL certificate must be provided for IP-HTTPS. There are three different types of SSL certificates that can be used.

Public SSL Certificate – Using an SSL certificate signed by a public certification authority (CA) is the recommended best practice for configuring DirectAccess IP-HTTPS. This provides the highest level of assurance for DirectAccess clients connecting via IP-HTTPS.

Private SSL Certificate – Using an SSL certificate issued by the organization’s internal CA is an acceptable alternative to using a public SSL certificate in most cases. This can reduce the cost associated with obtaining the certificate, especially for multisite deployments.

Self-Signed Certificate – Using a self-signed certificate is not recommended and should be avoided in most deployment scenarios. A self-signed certificate provides no real assurance for DirectAccess clients. Crucially, using a self-signed certificate will disable support for null SSL and TLS cipher suites. This reduces the overall scalability and performance of the remote access solution.

SSL Certificate Considerations for DirectAccess IP-HTTPS

Figure 1. Null cipher suites not supported when using a self-signed SSL certificate for IP-HTTPS.

Certificate Requirements

The SSL certificate must include the Server Authentication (1.3.6.1.5.5.7.3.1) Enhanced Key Usage (EKU) Object Identifier (OID). It should use an RSA key of 2048 bits and be signed with SHA256. Using stronger keys provides no additional protection and should not be used. In addition, SSL certificates using ECDSA keys is not recommended, as they do not support null cipher suites.

Summary

In most cases, using a public SSL certificate is ideal. However, issuing a certificate from a private CA is also acceptable. Using self-signed certificates can be used for non-production testing and in very small production deployments, but should generally be avoided.

Additional Resources

DirectAccess IP-HTTPS SSL and TLS Insecure Cipher Suites

DirectAccess and Multi-SAN SSL Certificates for IP-HTTPS

DirectAccess and NetMotion Mobility Webinar

Update: You can view the on-demand recording of this webinar here.

DirectAccess on Windows Server 2016 CoreFor many years, DirectAccess has been the gold standard for enterprise remote access. Its seamless and transparent operation improves productivity for mobile workers, and since it is always on, administrators enjoy improved visibility and management for their field-based assets.

As incredible as DirectAccess is, it is not without its limitations. For example, DirectAccess works only with Windows Enterprise edition clients that are joined to the domain. Professional Edition and non-domain joined machines are not supported. It also lacks many of the security features enterprise organizations require, such as device health checks and granular network access. In addition, DirectAccess communication is complex, with many different layers of encapsulation, authentication, and encryption. High protocol overhead can lead to poor performance over high latency or low bandwidth connections.

NetMotion Mobility as an Alternative to DirectAccessNetMotion Mobility is a secure remote access solution that is an excellent alternative to DirectAccess. It provides the same seamless, transparent, always on remote connectivity that DirectAccess provides, while at the same time offering much more in terms of features and capabilities. It supports a much broader range of clients, includes native Network Access Control (NAC) and application filtering, and offers enhanced performance.

To learn more about NetMotion Mobility, join me on Wednesday, September 20 at 10:00AM PDT for a free live webinar with NetMotion. I’ll provide an overview of NetMotion Mobility and how it compares with DirectAccess. I’ll also demonstrate how it can help overcome some of the inherent limitations of DirectAccess too. Register today!

DirectAccess and NetMotion Mobility Webinar

DirectAccess Force Tunneling and Proxy Server Configuration

By default, DirectAccess is configured to use split tunneling. In this scenario, a remote DirectAccess client is connected to the internal corporate network and the public Internet at the same time. Some security administrators perceive split tunneling as a security risk, and the use of split tunneling may be prohibited by corporate security policy. In addition, enforcing web browsing policies on remote DirectAccess clients might be desired to reduce the risk of exposure from browsing unapproved web sites. In either case, force tunneling can be configured to meet these requirements.

When force tunneling is enabled, DirectAccess administrators can also define an on-premises proxy server for DirectAccess clients to use. The following is guidance for enabling force tunneling and configuring DirectAccess clients to use a proxy server to access the Internet.

Enabling Force Tunneling

To enable force tunneling, open the Remote Access Management console and perform the following steps.

  1. Expand Configuration and select DirectAccess and VPN.
  2. Click Edit on Step 1 Remote Clients.
  3. Click Select Groups in the navigation tree.
  4. Select the option to Use force tunneling.

DirectAccess Force Tunneling and Proxy Server ConfigurationFigure 1. Enable DirectAccess force tunneling in the Remote Access Management console.

Alternatively, force tunneling can quickly be enabled by opening an elevated PowerShell command window and running the following command.

Set-DAClient -ForceTunnel Enabled -PassThru

DirectAccess Force Tunneling and Proxy Server ConfigurationFigure 2. Enable DirectAccess force tunneling using PowerShell.

Configure a Proxy Server

Once force tunneling has been enabled, run the following PowerShell script to configure an on-premises proxy server for DirectAccess clients to use. Be sure to substitute the fully-qualified domain name (FQDN) and port for your proxy server in the $proxy variable below.

$gpo = (Get-RemoteAccess).ClientGpoName
$gpo = $gpo.Split(‘\’)[1]

$proxy = “proxy.corp.example.net:8080”

$rule = (Get-DnsClientNrptRule -GpoName $gpo | Where-Object Namespace -eq “.” | Select-Object -ExpandProperty “Name”)

Set-DnsClientNrptRule -DAEnable $true -DAProxyServerName $proxy -DAProxyType “UseProxyName” -Name $rule -GpoName $gpo

If multisite is enabled and Windows 7 clients are supported, run the following PowerShell script on one DirectAccess server in each entry point.

$downlevelgpo = (Get-RemoteAccess).DownlevelGpoName
$downlevelgpo = $downlevelgpo.Split(‘\’)[1]

$proxy = “proxy.corp.example.net:8080”

$downlevelrule = (Get-DnsClientNrptRule -GpoName $downlevelgpo | Where-Object Namespace -eq “.” | Select-Object -ExpandProperty “Name”)

Set-DnsClientNrptRule -DAEnable $true -DAProxyServerName $proxy -DAProxyType “UseProxyName” -Name $downlevelrule -GpoName $downlevelgpo

Remove Proxy Server

Run the following PowerShell script to remove the proxy server, if necessary.

$gpo = (Get-RemoteAccess).ClientGpoName
$gpo = $gpo.Split(‘\’)[1]

Set-DnsClientNrptRule -DAEnable $true -DAProxyType “UseDefault” -Name $rule -GpoName $gpo

$downlevelgpo = (Get-RemoteAccess).DownlevelGpoName
$downlevelgpo = $downlevelgpo.Split(‘\’)[1]

Set-DnsClientNrptRule -DAEnable $true -DAProxyType “UseDefault” -Name $downlevelrule -GpoName $downlevelgpo

Disable Force Tunneling

To disable force tunneling completely, run the following PowerShell command.

Set-DAClient -ForceTunnel Enabled -PassThru

Force Tunneling Caveats

When force tunneling is enabled, the user experience is typically poor when accessing the Internet. Web browsing performance is significantly reduced because of the added protocol overhead imposed by DirectAccess IPv6 transition technologies and IPsec encryption. This problem is further compounded when users access resources that are already encrypted, such as secure web sites. Increased packet fragmentation, along with the additional network latency caused by suboptimal network paths and increased network load on the server and Internet connection all contribute to degraded network performance for DirectAccess clients.

Force Tunneling Alternatives

Instead of enabling force tunneling, consider alternative solutions to address the security concerns associated with split tunneling. For example, implement technologies that enforce web browsing policies on the client. Many secure web gateways and next-generation firewalls (NGFW) have remote filtering capabilities that allow administrators to enforce web browsing policies on remote client machines. In addition, there are some excellent cloud-based solutions such as Zscaler and OpenDNS that can protect DirectAccess clients without the drawbacks associated with force tunneling.

Additional Information

Planning and Implementing DirectAccess with Windows Server 2016 video training course on Pluralsight
Managing and Supporting DirectAccess with Windows Server 2016 video training course on Pluralsight
Implementing DirectAccess with Windows Server 2016 Book

Always On VPN and the Future of Microsoft DirectAccess

Windows 10 Always On VPN hands-on training classes now forming. Details here.

Since the introduction of Windows Server 2012 in September of 2012, no new features or functionality have been added to DirectAccess. In Windows Server 2016, the only real change aside from bug fixes for DirectAccess is the removal of Network Access Protection (NAP) integration support.

Always On VPN and the Future of Microsoft DirectAccessFigure 1. Remote Access Setup wizard with NAP integration option in Windows Server 2012/R2.

Always On VPN and the Future of Microsoft DirectAccess

Figure 2. Remote Access Setup wizard without NAP integration option in Windows Server 2016.

DirectAccess Roadmap

It’s clear to see that Microsoft is no longer investing in DirectAccess, and in fact their field sales teams have been communicating this to customers for quite some time now. Microsoft has been actively encouraging organizations who are considering a DirectAccess solution to instead implement client-based VPN with Windows 10.

Always On VPN

New features introduced in the Windows 10 Anniversary Update allow IT administrators to configure automatic VPN connection profiles. This Always On VPN connection provides a DirectAccess-like experience using traditional remote access VPN protocols such as IKEv2, SSTP, and L2TP/IPsec. It comes with some additional benefits as well.

  • Conditional access and device compliance with system health checks
  • Windows Hello for Business and Azure multifactor authentication
  • Windows Information Protection (WIP) integration
  • Traffic filters to restrict VPN network access
  • Application-trigger VPN connections

DirectAccess Deprecated?

There has been rampant speculation that Microsoft plans to deprecate and retire DirectAccess. While that may in fact be true, Microsoft has yet to make a formal end-of-life announcement. There’s no reason DirectAccess and VPN couldn’t co-exist, so it’s not a certainty Microsoft will do this. However, there’s also no need to have multiple remote access solutions, and it is abundantly clear that the future for Microsoft remote access is Always On VPN and not DirectAccess.

Always On VPN and the Future of Microsoft DirectAccess

Source: https://docs.microsoft.com/en-us/windows-server/remote/remote-access/vpn/vpn-top#advanced-vpn-connectivity

Always On VPN Advantages and Disadvantages

Windows 10 Always On VPN has some important advantages over DirectAccess. It has some crucial limitations as well.

Advantages

  • Always On VPN supports non-Enterprise Windows 10 client SKUs (Windows 10 Home and Professional)
  • Always On VPN includes support for granular network access control
  • Always On VPN can use both IPv4 and IPv6
  • Always On VPN is infrastructure independent. In addition to supporting Windows RRAS, any third-party network device can be used such as Cisco, Checkpoint, Juniper, Palo Alto, SonicWALL, Fortinet, Sophos, and many more

Disadvantages

  • Always On VPN works only with Windows 10. It is not supported for Windows 7
  • Always On VPN cannot be managed natively using Active Directory and group policy. It must be configured and managed using Microsoft System Center Configuration Manager (SCCM), Microsoft Intune, or PowerShell

DirectAccess or Always On VPN?

Should you deploy DirectAccess today or implement Always On VPN with Windows 10 instead? That depends on a number of factors. It’s important to understand that DirectAccess is fully supported in Windows Server 2016 and will likely be for many years to come. If DirectAccess meets your needs today, you can deploy it with confidence that it will still have a long support life. If you have reservations about the future viability of DirectAccess, and if you meet all of the requirements to support Always On VPN with Windows 10, then perhaps that’s a better choice. If you’d like to discuss your remote access options in more detail, fill out the form below and I’ll get in touch with you.

Additional Resources

5 Things DirectAccess Administrators Should Know About Always On VPN

3 Important Advantages of Always On VPN over DirectAccess

NetMotion Mobility as an Alternative to DirectAccess

Windows 10 Always On VPN Hands-On Training Classes

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