Outlook Offline over DirectAccess on Windows 10

Outlook Offline over DirectAccess on Windows 10You may encounter a scenario in which Outlook on Windows 10 reports that it is working offline while connected remotely via DirectAccess. The Network Connectivity Status Indicator (NCSI) shows DirectAccess is in a connected state and all other internal resources are accessible.

Outlook Offline over DirectAccess on Windows 10

This is caused by the default settings of the IP-HTTPS tunnel interface on the DirectAccess server not advertising a default route for connected DirectAccess clients. To resolve this issue, enable default route advertising for IP-HTTPS on each DirectAccess server in the enterprise by running the following PowerShell command.

Get-NetIPInterface | Where-Object {$_.InterfaceAlias -eq “IPHTTPSInterface”} | Set-NetIPInterface -AdvertiseDefaultRoute Enabled -PassThru

Outlook Offline over DirectAccess on Windows 10

In the past I’ve heard reports of this setting being overwritten after group policy refresh. Recent testing on Windows Server 2016 does not show this behavior, however. Please report any results you may have in the comments below. Thanks!

Always On VPN Device Tunnel Configuration Guidance Now Available

Always On VPN Device Tunnel Configuration Guidance Now AvailableWhen Always On VPN is configured for Windows 10, the VPN connection is established automatically when the user logs on to their device. This differs fundamentally from DirectAccess, where the connection is established by the machine, before the user logs on. This subtle but important difference has some important ramifications. For example, it means that a user cannot use Always On VPN until they’ve logged on to their device at least once while connected to the corporate network. DirectAccess doesn’t have this limitation, as a connection to an on-premises domain controller is available to authenticate a new user upon first logon.

Device Tunnel Support

To address this shortcoming with Always On VPN, and to provide better feature parity with DirectAccess, Microsoft introduced an update to Windows 10 in the recent Fall Creators update (v1709) that allows for the configuration of a device tunnel for Windows 10 Always On VPN. Once enabled, the device itself can automatically establish a secure remote connection before the user logs on. This enables scenarios such as device provisioning for new remote users without cached credentials. It also enables support for password reset using CTRL+ALT+DEL.

Manage Out

Device tunnel for Windows 10 Always On VPN also enables important manage out scenarios that DirectAccess administrators have come to rely upon. With a device tunnel configured, administrators can initiate connections to remote connected Always On VPN clients to provide remote management and support, without requiring a user to be logged on at the time.

Requirements

To support an Always On VPN device tunnel, the client must be running Windows 10 Enterprise or Education v1709 or later. The computer must be domain-joined and have a machine certificate installed. Device tunnel can only be configured using the built-in Windows 10 VPN client (no support for third-party clients) and the IKEv2 protocol must be used.

Caveat

When configuring a device tunnel, traffic filters can be implemented to restrict communication to only those internal resources required, such as domain controllers, Windows Server Update Services (WSUS) or System Center Configuration Manager (SCCM) servers. However, when traffic filters are used, no inbound traffic to the client is allowed. If manage out is required over the device tunnel, traffic filters cannot be configured. Microsoft expects to remove this limitation in a future update.

Provisioning and Documentation

Configuring and provisioning a Windows 10 Always On VPN device tunnel is similar to the process for the Always On VPN connection itself. A VPN profileXML file is created and then deployed via a Mobile Device Management (MDM) solution such as Microsoft Intune. Optionally, the VPN profileXML can be deployed using SCCM or PowerShell. Additional information about Windows 10 Always On VPN device tunnel configuration, including a sample profileXML and PowerShell script, can be found here.

Additional Resources

Configure a VPN Device Tunnel in Windows 10

Always On VPN and the Future of DirectAccess

5 Things DirectAccess Administrators Should Know about Always On VPN

PowerShell Recommended Reading for DirectAccess and Always On VPN Administrators

PowerShell Recommended Reading for DirectAccess and Always On VPN AdministratorsPowerShell is an important skill for administrators supporting Microsoft workloads including DirectAccess and Always On VPN. Using PowerShell to install required roles and features is much simpler and quicker than using the Graphical User Interface (GUI), with only a single command required to accomplish this task. Some settings aren’t exposed in the GUI and can only be configured using PowerShell. In addition, PowerShell makes the task of troubleshooting DirectAccess and Always On VPN much easier.

Learn PowerShell

One of the best resources for learning PowerShell is the book Learn PowerShell in a Month of Lunches authored by Microsoft MVPs and recognized PowerShell experts Don Jones and Jeff Hicks. This book, now in its third edition, should be considered essential reading for all Microsoft administrators. Click here for more details.

PowerShell Recommended Reading for DirectAccess and Always On VPN Administrators

Learn PowerShell Scripting

Recently Don and Jeff released a new book entitled Learn PowerShell Scripting in a Month of Lunches. This new book builds upon the skills learned in their first title by focusing on the development of PowerShell scripts to automate many common administrative tasks. PowerShell scripts can also be used to build custom, reusable tools to more effectively manage and monitor Microsoft workloads. Click here for more details.

PowerShell Recommended Reading for DirectAccess and Always On VPN Administrators

PowerShell for the Future

In my experience, far too many administrators today lack crucial PowerShell abilities. Don’t get left behind! PowerShell is rapidly becoming a required skill, so get these books and start learning PowerShell today!

Additional Resources

Top 5 DirectAccess Troubleshooting PowerShell Commands

Configure Windows Server Core to use PowerShell by Default

 

NetMotion Mobility as an Alternative to DirectAccess

Learn more about NetMotion Mobility by registering for my free live webinar here!

NetMotion Mobility as an Alternative to DirectAccessAs I outlined in a recent blog post, there has been much speculation surrounding the end of life for Microsoft DirectAccess. This is not surprising, as Microsoft has not made any investments in DirectAccess since the introduction of Windows Server 2012. Recently, Microsoft began promoting its Always On VPN solution as an alternative for DirectAccess. While DirectAccess has not been formally deprecated, Microsoft is actively encouraging organizations considering DirectAccess to deploy Always On VPN instead, as indicated here.

NetMotion Mobility as an Alternative to Microsoft DirectAccess

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

DirectAccess Alternatives

It’s important to state that, at the time of this writing, DirectAccess is still fully supported in Windows 10 and Windows Server 2016 and will be for quite some time. However, the future for DirectAccess is definitely limited, and customers should start considering alternative remote access solutions.

Always On VPN

Microsoft is positioning Always On VPN as the replacement for DirectAccess. Always On VPN offers some important new capabilities missing from DirectAccess. For example, Always On VPN supports all Windows 10 client SKUs, not just Enterprise and Education as DirectAccess does. Always On VPN includes important security enhancements such as conditional access with system health checks, access control list (ACL) enforcement per device and per application, and more.

Always On VPN Limitations

But Always On VPN has some serious limitations too. For example, Always On VPN works only with Windows 10. Windows 7 is not supported at all. Managing and supporting Always On VPN has its own challenges. It cannot be managed using Active Directory and group policy in the traditional way. You must use System Center Configuration Manager (SCCM), Intune, or PowerShell to configure and manage VPN clients.

NetMotion Mobility

I’m excited to announce I’ve recently partnered with NetMotion to provide their secure remote access solutions to organizations looking for alternatives to DirectAccess and Always On VPN. NetMotion Mobility provides the same seamless and transparent, always on remote access with some additional important features not included in DirectAccess and Always On VPN.

Broad Client Support – NetMotion Mobility can provide DirectAccess-like remote access for all versions and SKUs of Windows as well as Mac, iOS (iPhone and iPad), and Android.

Enhanced Security – NetMotion Mobility includes fine-grained policy enforcement to restrict network access based on a wide range of parameters including IP address, protocol, port, application, time of day, location, and type of network (e.g. wired, Wi-Fi, wireless, etc.). NetMotion Mobility also includes integrated Network Access Control (NAC) to validate device configuration prior to connecting, ensuring the highest level of security for remote endpoints. More details here and here.

Improved Performance – NetMotion Mobility client to server communication is optimized to improve reliability and performance. Network traffic is compressed and prioritized to ensure optimum performance for critical applications. Session persistence allows mobile workers to remain connected during times of poor connectivity or when roaming between different networks. More details here.

Greater Visibility – NetMotion Mobility provides a wealth of detailed information to perform analysis and troubleshooting for remote connections. Performance and diagnostic information is logged in real-time and provides administrators with crucial data and insight to quickly identify and resolve connectivity issues. More details here.

Better Supportability – NetMotion Mobility is supported by dedicated, highly trained support engineers with deep product experience. NetMotion support is not tiered. The support engineer who answers the phone will handle the case until resolution.

Learn More about NetMotion

NetMotion Mobility is a truly comprehensive remote access solution and an excellent alternative to DirectAccess. To learn more about NetMotion Mobility and to see it in action, fill out the form below and I’ll get in touch with you. You can also register for my upcoming free live webinar here.

Additional Information

Webinar: Comparing DirectAccess and NetMotion Mobility

Always On VPN and the Future of DirectAccess

NetMotion and DirectAccess Comparison Whitepaper

NetMotion and Skype for Business demonstration video

NetMotion Website

Top 5 DirectAccess Troubleshooting Tips

Top 5 DirectAccess Troubleshooting TipsDirectAccess is a thing of beauty when everything is working as it should. When it isn’t, troubleshooting can be quite challenging. DirectAccess relies on many Windows platform technologies such as Active Directory for authentication, PKI for certificate management, group policy for settings deployment, IPsec for encryption, and IPv6 for transport. With so many dependencies, locating the source of the problem can be a difficult and daunting task.

I’m frequently called upon to help organizations of all sizes with DirectAccess troubleshooting. While this post is not intended to be a detailed, prescriptive guide for DirectAccess troubleshooting, I did want to share some common troubleshooting tips based on many years of troubleshooting DirectAccess.

Here are my top 5 DirectAccess troubleshooting tips:

  1. Check Prerequisites – Before diving in and collecting network traces and scouring event logs for clues as to why DirectAccess isn’t working, it’s essential to start at the beginning. Often the source of trouble is missing or misconfigured prerequisites. For example, is the DirectAccess client running a supported operating system? Remember, clients must be running Windows 10 Enterprise or Education, Windows 8.x Enterprise, or Windows 7 Enterprise or Ultimate. Also, ensure that the Windows firewall is enabled on DirectAccess servers and clients, that certificates are installed and valid (trusted, correct EKU, etc.), and that the DirectAccess settings GPO has been applied to servers and clients.
  2. Validate External Connectivity – If you are following implementation and security best practices for DirectAccess, the DirectAccess server will be in a perimeter/DMZ network behind an edge firewall. The firewall must be configured to allow inbound TCP port 443 only. If the firewall is also performing Network Address Translation (NAT), the NAT rule must be configured to forward traffic to the DirectAccess server’s dedicated or virtual IP address (VIP), or the VIP of the load balancer. Watch for routing issues when using load balancers too. It’s a good idea to confirm external connectivity using the Test-NetConnection PowerShell command. Even better, use the open source tool Nmap for more thorough testing.
  3. Remove Third Party Software – I can’t tell you how many times I’ve resolved DirectAccess connectivity issues by removing (not just disabling!) third party software on the client and/or server. It’s not uncommon for third-party security software to interfere with IPsec and/or IPv6 communication, both of which are vital to DirectAccess. If your DirectAccess troubleshooting efforts reveal no underlying issues with prerequisites or external connectivity, I’d suggest removing (at least temporarily) any third-party software and testing again.
  4. Isolate Environmental Issues – Occasionally other settings applied manually or via Active Directory group policy will interfere with DirectAccess. Examples include IPv6 being disabled in the registry, IPv6 transition technologies required to support DirectAccess are turned off, essential firewall rules for DirectAccess are disabled, or manipulating local security settings such as Access this computer from the network. To assist with troubleshooting it might be necessary to temporarily place DirectAccess clients and servers in their own dedicated Organizational Units (OUs) and block inheritance to isolate the configuration as much as possible. In addition, if DirectAccess clients are servers are provisioned using images or templates, testing with a clean build straight from the installation source (ISO or DVD) can be helpful.
  5. Check for Unsupported Configurations – If DirectAccess isn’t working, it might be possible the configuration you are trying to use is not supported. Examples including strong user authentication with OTP when force tunneling is enabled, provisioning Windows 7 clients when using Kerberos Proxy authentication, or provisioning Windows 10 clients when Network Access Protection (NAP) integration is enabled. These configurations won’t work and are formally documented here.

This is by no means a comprehensive or exhaustive troubleshooting guide. For more information and additional DirectAccess troubleshooting guidance I would encourage you to purchase my book Implementing DirectAccess with Windows Server 2016, which has an entire chapter devoted just to troubleshooting. In addition, watch my DirectAccess video training courses on Pluralsight for details and information about DirectAccess installation, configuration, management, support, and troubleshooting. And if you’re still struggling to resolve a DirectAccess problem, use the form at the bottom of this page to contact me to inquire about additional troubleshooting help.

Additional Resources

Microsoft Windows DirectAccess Client Troubleshooting Tool
DirectAccess and Windows 10 Professional
DirectAccess Troubleshooting with Nmap
DirectAccess Unsupported Configurations
Planning and Implementing DirectAccess with Windows Server 2016 Video Training Course on Pluralsight
Implementing DirectAccess with Windows Server 2016 Book

Need assistance with DirectAccess troubleshooting? Complete the form below and I’ll get in touch with you.

DirectAccess Troubleshooting with Nmap

DirectAccess IP-HTTPS Discovery Script for NmapDirectAccess troubleshooting can be made much easier using open source tools such as Nmap. Nmap can be used to perform many essential network connectivity and configuration checks, including validating network paths, confirming DirectAccess server response, and viewing SSL configuration. Nmap can also be used to ensure that the attack surface of the DirectAccess server is properly minimized. Some tests can be performed using only native Nmap functionality, while others require the use of specialized Nmap scripts that are included with the tool.

Installation

Nmap can be installed on a wide variety of operating systems, including Windows. If you plan to install Nmap on Windows, be sure to also install WinPcap and the Microsoft Visual C++ 2013 Redistributable. The Visual C++ component is included with the Nmap download. WinPcap must be downloaded separately here.

Testing External Connectivity

Validating external connectivity is often one of the first DirectAccess troubleshooting steps I take. Confirm that the DirectAccess public hostname resolves to the correct IP address, then run the following Nmap command to validate network connectivity from the Internet to the DirectAccess server.

nmap -n -Pn -p443 <da_public_hostname>

DirectAccess Troubleshooting with Nmap

If the hostname resolves correctly and the network path is complete, the server should respond and Nmap will show the port as open. However, this doesn’t necessarily mean that the DirectAccess server is the device that replied! Due to misconfiguration, it is possible that another server or network device listening on TCP port 443 responded, so this is not a conclusive test.

DirectAccess Server Response

To confirm the DirectAccess server is responding to HTTPS requests and not some other server or device, run the following Nmap command with the ip-https-discover script.

nmap -n -Pn -p443 <da_public_hostname> –script ip-https-discover

If the DirectAccess server responds to the request, Nmap will return the following message:

IP-HTTPS is supported. This indicates that this host supports Microsoft DirectAccess.

DirectAccess Troubleshooting with Nmap

If the port is open but the script does not return this message, it is likely that another server or device is responding on TCP port 443, not the DirectAccess server.

Note: If an Application Delivery Controller (ADC) is configured to perform IP-HTTPS preauthentication, the Nmap IP-HTTPS discovery script will not return this result. This is expected and by design.

SSL Certificate Validation

It is not uncommon for DirectAccess clients to fail to connect via IP-HTTPS because of SSL certificate issues. Specifically, an SSL certificate that is not trusted, is expired, or its subject field does not match the public hostname will prevent DirectAccess clients from connecting. To view the SSL certificate configuration of a DirectAccess server, run the following Nmap command with the ssl-cert script.

nmap -n -Pn -p443 <da_public_hostname> –script ssl-cert

DirectAccess Troubleshooting with Nmap

SSL Cipher Suite Configuration

Occasionally there can be issues with the SSL configuration on the DirectAccess server that prevent some clients from connecting, or result in poor performance. This commonly occurs when administrators perform SSL hardening on the DirectAccess server and remove support for null cipher suites. Null cipher suites should never be disabled on the DirectAccess server. They are important to ensure the highest levels of performance for Windows 8.x and Windows 10 clients. Also, if an Application Delivery Controller (ADC) or load balancer is performing SSL offload, lack of support for null cipher suites will prevent Windows 8.x and Windows 10 clients from connecting. To determine if the DirectAccess server supports null cipher suites, run the following Nmap command with the ssl-enum-ciphers script.

nmap -n -Pn -p443 <da_public_hostname> –script ssl-enum-ciphers

DirectAccess Troubleshooting with Nmap

Attack Surface Audit

If DirectAccess implementation and security best practices are followed, the DirectAccess server will be behind an edge firewall. The only port required to be allowed inbound for DirectAccess is TCP port 443. It is recommended that a full port scan be performed against the DirectAccess server’s public IPv4 address to identify any unnecessary ports that may be open externally. To perform a full port scan, run the following Nmap command.

nmap -n -Pn -p- <da_public_hostname>

Ideally it should look like this.

DirectAccess Troubleshooting with Nmap

If it looks something like this, you’re in serious trouble!

DirectAccess Troubleshooting with Nmap

The DirectAccess server should never be listening for requests other that HTTPS on the public Internet. Exposing services such as SMB (TCP port 445), RDP (TCP port 3389), and others presents a significant security risk. It is recommended that edge firewalls be configured to allow inbound TCP port 443 only. If the DirectAccess server is connected directly to the public Internet (not recommended!) then the Windows Firewall should be configured to restrict access to inbound TCP port 443 only.

Additional Resources

DirectAccess IP-HTTPS Discovery Script for Nmap
Planning and Implementing DirectAccess with Windows Server 2016 on Pluralsight
Implementing DirectAccess with Windows Server 2016 Book
DirectAccess Troubleshooting and Consulting Services

DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler

Introduction

Communication between the DirectAccess client and server takes place exclusively over IPv6. When DirectAccess servers and/or clients are on the IPv4 Internet, an IPv6 transition technology must be employed to allow those clients to connect to the DirectAccess server. DirectAccess deployment best practices dictate that only the IP-HTTPS IPv6 transition technology be used. IP-HTTPS uses SSL/TLS for server authentication and optionally encryption. To improve security and performance for IP-HTTPS, an Application Delivery Controller (ADC) like the Citrix NetScaler can be configured to perform SSL offloading and client preauthentication for DirectAccess IP-HTTPS connections.

Please note that the following caveats apply when enabling SSL offload for DirectAccess clients:

  • Enabling SSL offload and IP-HTTPS preauthentication on an ADC for DirectAccess is formally unsupported by Microsoft.
  • SSL offload should not be enabled with DirectAccess is configured to use one-time password (OTP) authentication. Offloading SSL will break OTP functionality.

IP-HTTPS Challenges

The IP-HTTPS IPv6 transition technology is a simple and effective way to allow DirectAccess clients and servers to communicate by encapsulating IPv6 traffic in HTTP and routing it over the public IPv4 Internet. However, there are two critical issues with the default implementation of IP-HTTPS in DirectAccess. One is a security issue, the other affects performance.

Security

The DirectAccess server does not authenticate clients establishing IP-HTTPS connections. This could allow an unauthorized client to obtain an IPv6 address from the DirectAccess server using the IPv6 Neighbor Discovery (ND) process. With a valid IPv6 address, the unauthorized user could perform internal network reconnaissance or launch a variety of Denial of Service (DoS) attacks on the DirectAccess infrastructure and connected clients. More details here.

Performance

Windows 7 DirectAccess clients use encrypted cipher suites when establishing IP-HTTPS connections. However, the payload being transported is already encrypted using IPsec. This double encryption increases resource utilization on the DirectAccess server, reducing performance and limiting scalability. More details here.


Note: Beginning with Windows Server 2012 and Windows 8, Microsoft introduced support for null encryption for IP-HTTPS connections. This eliminates the needless double encryption, greatly improving scalability and performance for DirectAccess clients using IP-HTTPS.


SSL Offload for DirectAccess IP-HTTPS

The Citrix NetScaler can be configured to perform SSL offload to improve performance for Windows 7 DirectAccess clients using IP-HTTPS. Since DirectAccess does not natively support SSL offload, the NetScaler must be configured in a non-traditional way. While the NetScaler will be configured to terminate incoming IP-HTTPS SSL connections, it must also use SSL for the back-end connection to the DirectAccess server. However, the NetScaler will be configured only to use null cipher suites when connecting to the DirectAccess server. Even though Windows 7 clients will still perform double encryption to the NetScaler, this configuration effectively offloads from the server the heavy burden of double encrypting every IP-HTTPS connection for all connected DirectAccess clients. This results in reduced CPU utilization on the DirectAccess server, yielding better scalability and performance.

SSL Offload and Windows 8.x/10 Clients

Offloading SSL for Windows 8.x/10 clients will not improve performance because they already use null cipher suites for IP-HTTPS when connecting to a Windows Server 2012 or later DirectAccess server. However, terminating SSL on the NetScaler is still required to perform IP-HTTPS preauthentication.

Supported NetScaler Platforms for DirectAccess SSL Offloading

The following configuration for Citrix NetScaler can be performed on any release of the VPX virtual ADC platform. However, be advised that there is a known issue with older releases on the MDX and SDX hardware platforms that will prevent this from working. For MDX and SDX deployments, upgrading to release 11.1 build 50.10 or later will be required.

Configure Citrix NetScaler for IP-HTTPS SSL Offload

To enable SSL offloading for DirectAccess IP-HTTPS on the Citrix NetScaler, open the NetScaler management console, expand Traffic Management and Load Balancing, and then perform the following procedures in order.

Add Servers

  1. Click Servers.
  2. Click Add.
  3. In the Name field enter a descriptive name for the first DirectAccess server.
  4. Select IP Address.
  5. In the IP Address field enter the IP address of the first DirectAccess server.
  6. Click Create.
  7. Repeat these steps for any additional servers in the load-balanced cluster.

DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler

Add Services

  1. Click Services.
  2. Click Add.
  3. In the Service Name field enter a descriptive name for the service.
  4. Select Existing Server from the Server drop-down list.
  5. Choose the first DirectAccess server in the cluster.
  6. Choose SSL from the Protocol drop-down list.
  7. Click Ok.DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler
  8. Edit SSL Parameters.
    1. In the Protocol section uncheck SSLv3.
    2. Click Ok.
  9. Edit SSL Ciphers.
    1. Click Remove All.
    2. Click Add.
    3. Type NULL in the Search Ciphers box.
    4. Check the box next to the first entry for SSL3-NULL-SHA.
    5.  Click the right arrow to add the cipher to the list.
    6. Click Ok.
    7. Click Done.
    8. Repeat these steps for any additional servers in the load-balanced cluster.DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler

A warning message may be displayed indicating that no usable ciphers are configured on the SSL vserver/service. This message can be safely ignored.

DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler

Add Virtual Server

  1. Click Virtual Servers.
    1. Click Add.
    2. In the Name field enter a descriptive name for the virtual server.
    3. Choose SSL from the Protocol drop-down list.
    4. In the IP Address field enter the IP address for the virtual server.
    5. Click Ok.DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler

      Note: When enabling load balancing in DirectAccess, the IP address assigned to the first DirectAccess server is reallocated for use as the load balancing Virtual IP Address (VIP). Ideally this IP address will be assigned to the load balancing virtual server on the NetScaler. However, this is not a hard requirement. It is possible to configure the VIP on the NetScaler to reside on any subnet that the load balancer has an interface to. More details here.


  2. In the Services and Groups section click No Load Balancing Virtual Server Service Binding.
    1. Click on the Select Service field.
    2. Check all DirectAccess server services and click Select.
    3. Click Bind.
    4. Click Continue.
  3. In the Certificate section click No Server Certificate.
    1. Click on the Select Server Certificate field.
    2. Choose the certificate to be used for DirectAccess IP-HTTPS.
    3. Click Select.
    4. Click Bind.
    5. Click Continue.
  4. Edit SSL Ciphers.
    1. Click Remove All.
    2. Click Add.
    3. Type ECDHE in to the Search Ciphers box.
    4. Check the box next to TLS1-ECDHE-RSA-AES128-SHA.
    5. Click the right arrow to add the cipher to the list.
    6. Type NULL in to the Search Ciphers box.
    7. Check the box next to SSL3-NULL-SHA.
    8. Click the right arrow to add the cipher to the list.
    9. Click Ok.
    10. Click Done.DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler

      Note: If Windows 8.x/10 clients are supported exclusively, SSL3-NULL-SHA is the only cipher suite required to be configured on the virtual server. If Windows 7 client support is required, the TLS1-ECDHE-RSA-AES128-SHA cipher suite should also be configured on the virtual server.


  5. Edit SSL Parameters.
    1. Uncheck SSLv3.
    2. Click Ok.

      Note: If Windows 8.x/10 clients are supported exclusively, TLSv1 can also be unchecked on the virtual server. If Windows 7 client support is required, TLSv1 must be enabled.


  6. In the Advanced Settings section click Persistence.
    1. Choose SSLSESSION.
    2. Enter 10 minutes for the Time-out (mins) value.
    3. Click Ok.
    4. Click Done.

Optional IP-HTTPS Preauthentication

To enable IP-HTTPS preauthentication to prevent unauthorized network access, perform the following procedures on the Citrix NetScaler appliance.

  1. Expand Traffic Management, Load Balancing, and then click Virtual Servers.
  2. Select the DirectAccess virtual server and click Edit.
    1. In the Certificate section click No CA Certificate.
    2. Click the Select CA Certificate field.
    3. Choose the certificate for the CA that issues certificates to DirectAccess clients and servers.

      Note: The CA certificate used for DirectAccess can be found by opening the Remote Access Management console, clicking Edit on Step 2, and then clicking Authentication. Alternatively, the CA certificate can be found by running the following PowerShell command.

      (Get-RemoteAccess).IPsecRootCertificate | Format-Table Thumbprint


    4. Click Select.
    5. Choose CRL Optional from the CRL and OCSP Check drop-down list.
    6. Click Bind.
  3. Edit SSL Parameters.
    1. Check the box next to Client Authentication.
    2. Choose Mandatory from the Client Certificate drop-down list.
    3. Click Ok.
    4. Click Done.
      DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler

Summary

Leveraging the advanced capabilities of the Citrix NetScaler ADC can improve performance when supporting Windows 7 clients and enhance security for all DirectAccess clients using IP-HTTPS. In terms of supportability, all of the changes described in this article are completely transparent and do not alter the native DirectAccess client or server configuration. If a Microsoft support engineer declines support due to this configuration, switching from SSL offload to SSL bridge is all that’s required to restore full supportability.

Additional Resources

NetScaler release 11.1 build 50.10 (requires login) – https://www.citrix.com/downloads/netscaler-adc/firmware/release-111-build-5010

Release notes for build 50.10 of NetScaler 11.1 release – https://www.citrix.com/content/dam/citrix/en_us/documents/downloads/netscaler-adc/NS_11_1_50_10.html

VIDEO: Enable Load Balancing for DirectAccess – https://www.youtube.com/watch?v=3tdqgY9Y-uo

DirectAccess IP-HTTPS preauthentication using F5 BIG-IP – https://directaccess.richardhicks.com/2016/05/23/directaccess-ip-https-preauthentication-using-f5-big-ip/

DirectAccess SSL offload for IP-HTTPS using F5 BIG-IP – https://directaccess.richardhicks.com/2013/07/10/ssl-offload-for-ip-https-directaccess-traffic-from-windows-7-clients-using-f5-big-ip/

Implementing DirectAccess with Windows Server 2016 book – http://directaccessbook.com/

DirectAccess Broken in Windows 10 Insider Preview Build 14971

DirectAccess Broken in Windows 10 Enterprise Insider Preview Build 14971Updated 12/9/2016: This issue has been resolved in build 14986. If you are still running build 14971, update to the latest build to resolve this issue.

For anyone running the Insider Preview version of Windows 10 Enterprise, be advised that the latest Fast Ring build (14971) has a bug that breaks DirectAccess connectivity. Microsoft is aware of the issue and is currently working to identify the root cause. As it stands now, there is no known workaround.

I’ll post an update as soon as I have more information. Stay tuned!

DirectAccess Training at TechMentor Conference Orlando 2016

Live! 360 Orlando 2016I am pleased to announce that I’ll be participating in the upcoming TechMentor conference in Orlando, FL in December. The TechMentor conference is part of the larger Live!360 event and offers a compelling agenda of training for IT professionals. I’ll be delivering the following sessions that are focused on providing secure remote access using Windows Server 2016.

TMT01 – Implementing DirectAccess in Windows Server 2016
TMT04 – DirectAccess Troubleshooting Deep Dive
TMT11 – Client-based VPN in Azure with Windows Server 2016

Don’t miss out on this outstanding conference. Register today and save $500.00!

Implementing DirectAccess with Windows Server 2016 Book Now Available

I am very excited to announce that my new DirectAccess book, Implementing DirectAccess with Windows Server 2016 from Apress media, is now shipping! The book is available on popular online sites like Amazon.com, Barnes & Noble, Springer.com, Apress.com, and others. The book is also available in electronic formats such as Amazon Kindle and Barnes & Noble Nook, as well as a variety of subscription formats including Safari, Books24x7, and SpringerLink.

Implementing DirectAccess with Windows Server 2016

This book contains detailed and prescriptive guidance for the planning, design, implementation, and support of a DirectAccess remote access solution on Windows Server 2016. It also includes valuable insight, tips, tricks, and best practice recommendations gained from my many years of deploying DirectAccess for some of the largest organizations in the world.

Current DirectAccess administrators will also find this book helpful, as the majority of content is still applicable to DirectAccess in Windows Server 2012 and Windows Server 2012 R2. In addition, the book also includes essential information on the design and deployment of highly available and geographically redundant DirectAccess deployments.

Troubleshooting DirectAccess can be a daunting task, so I’ve dedicated an entire chapter in the book to this topic. For those responsible for the maintenance and support of DirectAccess in their organization, this chapter alone will be worth the investment.

Be sure to order your copy today!

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