DirectAccess Reporting Fails and Schannel Event ID 36871 after Disabling TLS 1.0

When performing security hardening on the DirectAccess server it is not uncommon to disable weak cipher suites or insecure protocols such as SSL 3.0 and TLS 1.0. However, after disabling SSL 3.0 and TLS 1.0 you will find that it is no longer possible generate reports. Clicking the Generate Report link in the Remote Access Management console returns no data.

DirectAccess Reporting Fails after Disabling TLS 1.0

In addition, the System event log indicates Schannel errors with Event ID 36871. The error message states that “A fatal error occurred while creating a TLS client credential. The internal error state is 10013.”

DirectAccess Reporting Fails after Disabling TLS 1.0

To resolve this issue and restore DirectAccess reporting functionality you must enable the use of FIPS compliant encryption algorithms on the DirectAccess server. This change can be made locally or via Active Directory group policy. Open the Group Policy Management Console (gpmc.msc) for Active Directory GPO, or the Local Group Policy Editor (gpedit.msc) on the DirectAccess server and navigate to Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options. Double-click System cryptography: Use FIPS compliant algorithms for encryption, hashing, and signing and select Enabled.

DirectAccess Reporting Fails after Disabling TLS 1.0

If using Active Directory GPO, ensure that the GPO is applied all DirectAccess servers in the organization. A restart is not required for this setting to take effect. Once this change has been made, reporting should work as expected.

Additional Resources

DirectAccess IP-HTTPS SSL and TLS Insecure Cipher Suites
DirectAccess Video Training Courses on Pluralsight
Implementing DirectAccess with Windows Server 2016 Book on Amazon.com

DirectAccess Manage Out and System Center Configuration Manager (SCCM)

The seamless and transparent nature of DirectAccess makes it wonderfully easy to use. In most cases, it requires no user interaction at all to access internal corporate resources while away from the office. This enables users to be more productive. At the same time, it offers important connectivity benefits for IT administrators and systems management engineers as well.

Always Managed

DirectAccess Manage Out and System Center Configuration Manager (SCCM)DirectAccess clients are automatically connected to the corporate network any time they have a working Internet connection. Having consistent corporate network connectivity means they receive Active Directory group policy updates on a regular basis, just as on-premises systems do. Importantly, they check in with internal management systems such as System Center Configuration Manager (SCCM) and Windows Server Update Services (WSUS) servers, enabling them to receive updates in a timely manner. Thus, DirectAccess clients are better managed, allowing administrators to more effectively maintain the configuration state and security posture for all their managed systems, including those that are predominantly field-based. This is especially crucial considering the prevalence WannaCry, Cryptolocker, and a variety of other types of ransomware.

DirectAccess Manage Out

DirectAccess Manage Out and System Center Configuration Manager (SCCM)When manage out is configured with DirectAccess, hosts on the internal network can initiate connections outbound to remote connected DirectAccess clients. SCCM Remote Control and Remote Desktop Connection (RDC) are commonly used to remotely connect to systems for troubleshooting and support. With DirectAccess manage out enabled, these and other popular administrative tools such as VNC, Windows Remote Assistance, and PowerShell remoting can also be used to manage remote DirectAccess clients in the field. In addition, enabling manage out allows for the proactive installation of agents and other software on remote clients, such as the SCCM and System Center Operation Manager (SCOM) agents, third-party management agents, antivirus and antimalware software, and more. A user does not have to be logged on to their machine for manage out to work.

IPv6

DirectAccess manage out requires that connections initiated by machines on the internal network to remote-connected DirectAccess clients must be made using IPv6. This is because DirectAccess clients use IPv6 exclusively to connect to the DirectAccess server. To enable connectivity over the public IPv4 Internet, clients use IPv6 transition technologies (6to4, Teredo, IP-HTTPS), and IPv6 translation components on the server (DNS64 and NAT64) enable clients to communicate with internal IPv4 resources. However, DNS64 and NAT64 only translate IPv6 to IPv4 inbound. They do not work in reverse.

Native or Transition?

It is recommended that IPv6 be deployed on the internal network to enable DirectAccess manage out. This is not a trivial task, and many organizations can’t justify the deployment for just this one specific use case. As an alternative, IPv6 can be configured with an IPv6 transition technology, specifically the Intrasite Automatic Tunnel Addressing Protocol (ISATAP). ISATAP functions as an IPv6 overlay network, allowing internal hosts to obtain IPv6 addresses and routing information from an ISATAP router to support manage out for DirectAccess clients.

ISATAP

When DirectAccess is installed, the server is automatically configured as an ISATAP router. Guidance for configuring ISATAP clients can be found here. Using ISATAP can be an effective approach to enabling DirectAccess manage out for SCCM when native IPv6 is not available, but it is not without its drawbacks.

• Using the DirectAccess server for ISATAP is only supported with single server DirectAccess deployments.
• Using the DirectAccess server for ISATAP does work when using Network Load Balancing (NLB) with some additional configuration, but it is not supported.
• Using the DirectAccess server for ISATAP does not work when an external load balancer is used, or if multisite is enabled.

ISATAP with Load Balancing and Multisite

It is technically possible to enable DirectAccess manage out for SCCM using ISATAP in load-balanced and multisite DirectAccess deployments, however. It involves deploying a separate ISATAP router and some custom configuration, but once in place it works perfectly. I offer this service to my customers as part of a consulting engagement. If you’re interested in restoring DirectAccess manage out functionality to support SCCM remote control, RDC, or VNC in load-balanced or multisite DirectAccess deployments, fill out the form below and I’ll provide you with more information.

Additional Resources

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
Video: Windows 10 DirectAccess in action (includes manage out demonstration)

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

Planning and Implementing DirectAccess with Windows Server 2016I’m pleased to announce my newest video training course, Managing and Supporting DirectAccess with Windows Server 2016, is now available on Pluralsight! This new course is a follow-up to my previous course, Planning and Implementing DirectAccess with Windows Server 2016. This latest course builds upon the first one and covers advanced configuration such as enabling load balancing, configuring geographic redundancy, and enforcing strong user authentication using one-time passwords (OTP) and smart cards.

In addition, monitoring and reporting is covered, as well as implementing manage out for DirectAccess clients in supported scenarios. The course also includes a full hour of in-depth DirectAccess configuration and connectivity troubleshooting that will be valuable for all DirectAccess administrators.

The course includes the following training modules:

Configuring High Availability
Enabling Strong User Authentication
DirectAccess Monitoring and Reporting
Implementing Outbound Management for DirectAccess Clients
DirectAccess Troubleshooting

Throughout the course, I share valuable knowledge and insight gained from more than 5 years of experience deploying DirectAccess for some of the largest organizations in the world. Pluralsight offers a free trial subscription if you don’t already have one, so watch my latest DirectAccess video training course today!

Additional Resources

Planning and Implementing DirectAccess with Windows Server 2016 on Pluralsight
Managing and Supporting DirectAccess with Windows Server 2016 on Pluralsight
Implementing DirectAccess with Windows Server 2016 book

DirectAccess Network Connectivity Assistant (NCA) Configuration Guidance

DirectAccess Network Connectivity Assistant (NCA) Configuration GuidanceThe DirectAccess Network Connectivity Assistant (NCA), first introduced in Windows 8, provides DirectAccess connectivity status information as well as diagnostic support on the client. The NCA validates that DirectAccess is working end-to-end by attempting to reach internal resources defined by the administrator during the configuration of DirectAccess. NCA configuration and operation is a source of much confusion. This article serves to provide best practice configuration guidance for the NCA to ensure optimum and reliable operation.

NCA Operation

When a DirectAccess client is outside the corporate network, it will attempt to establish a DirectAccess connection any time it has an active Internet connection. After a DirectAccess connection is made, the NCA will attempt to validate DirectAccess connectivity by verifying availability of corporate resources as defined in the DirectAccess configuration (Remote Access Management console, Step 1, Edit, Network Connectivity Assistant).

If the NCA can reach the defined internal corporate resource(s), the DirectAccess connection is verified end-to-end and it will report the connection status as “Connected”. If it fails to connect to any internal corporate resource, it displays “Connecting”.

DirectAccess Network Connectivity Assistant (NCA) Configuration Guidance

Figure 1. NCA successfully validated internal corporate resource connectivity.

DirectAccess Network Connectivity Assistant (NCA) Configuration Guidance

Figure 2. NCA failed to connect to one or more corporate resources.

NCA Configuration

When first installing DirectAccess, the Remote Access Setup wizard will collect information to be used by the NCA, including corporate resources, helpdesk email address, and DirectAccess connection name. It will also provide the option to allow DirectAccess clients to use local name resolution.

Note: The NCA settings configured in the Remote Access Management console pertain only to Windows 8.x and Windows 10 clients. They are not used by Windows 7 clients at all.

DirectAccess Network Connectivity Assistant (NCA) Configuration Guidance

Intuitively it would appear that information needs to be entered in the Resource and Type fields. However, it is recommended to leave this blank when first configuring DirectAccess. This is because the Remote Access Setup Wizard will automatically populate this field later. Specifying a resource during initial configuration will result in two entries being included, as shown here.

DirectAccess Network Connectivity Assistant (NCA) Configuration Guidance

As you can see, the Remote Access Setup wizard automatically added the resource directaccess-WebProbeHost.<internal domain.>. A corresponding DNS record is created that resolves this hostname to the internal IPv4 address of the DirectAccess server. In this configuration, the DirectAccess server itself serves as the corporate resource used by the NCA.

Multiple Corporate Resources

Having more than one resource to validate connectivity to the internal network is problematic though. If there are multiple entries specified, they must ALL pass a validation check from the client to report the connection status as “Connected”. Some administrators configure multiple entries with the mistaken belief that it will provide redundancy for the NCA, but it actually has the opposite effect. Having more than one entry only increases the chance of a false positive.

NCA Configuration Best Practices

It is recommended that only a single corporate resource URL be defined for the NCA. The default directaccess-WebProbeHost running on the DirectAccess server can be used, or, alternatively, another internal web server can be specified if desired. Any web server will work, including Microsoft Internet Information Services (IIS), Apache, NGINX, and most Application Delivery Controllers (ADCs) or load balancers. HTTPS is not required for the web probe host, only HTTP. If using an internal web server, ensure that it is highly available.

Do NOT use the Network Location Server (NLS) as a corporate resource! The NLS is exempted from the Name Resolution Policy Table (NRPT) on the client and is not reachable over DirectAccess. This will result in the NCA failing and reporting a “Connecting” status perpetually. In addition, avoid the use of PING for validating internal corporate resources. Ping uses ICMP which is inherently unreliable and commonly blocked by host and intermediary firewalls, making it an unreliable indicator of corporate network connectivity over DirectAccess.

Summary

The NCA is a crucial and often misunderstood component in the DirectAccess architecture. Follow the guidance outlined here to ensure that the NCA works reliably and effectively in your environment.

Additional Resources

DirectAccess Clients in Connecting State when using External Load Balancer
Planning and Implementing DirectAccess on Windows Server 2016 on Pluralsight
Implementing DirectAccess with Windows Server 2016 book

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.

KEMP LoadMaster Load Balancer Certificate Format Invalid

When implementing a KEMP LoadMaster load balancer, one of the first configuration tasks performed is importing root and intermediate Certification Authority (CA) certificates. When doing this, it is not uncommon to encounter the following error message.

Certificate Format Invalid.

KEMP LoadMaster Load Balancer Certificate Invalid

To resolve this issue, .CER files must first be converted to .PEM format before being imported in to the LoadMaster. Using OpenSSL, .CER files can quickly be converted to .PEM with the following command.

openssl x509 -inform der -in example.cer -out example.pem

Optionally, .CER files can be converted to .PEM online here.

If the root and/or intermediate certificates are from an internal PKI, export the certificates using the Base-64 encoded x.509 (.CER) option. Certificates exported using this format can be imported directly in to the LoadMaster without first having to be converted to .PEM.

KEMP LoadMaster Load Balancer Certificate Format Invalid

Pro tip: When entering the Certificate Name, it is not necessary to enter a file extension. The name will be appended with .PEM automatically upon import.

KEMP LoadMaster Load Balancer Certificate Format Invalid

KEMP LoadMaster Load Balancer Certificate Format Invalid

Additional Resources

DirectAccess Deployment Guide for KEMP LoadMaster Load Balancers

Maximize Your Investment in Windows 10 with KEMP LoadMaster Load Balancers

DirectAccess and the FREE KEMP LoadMaster Load Balancer

Configure KEMP LoadMaster Load Balancer for DirectAccess Network Location Server (NLS)

Planning and Implementing DirectAccess Video Training Course on Pluralsight

Implementing DirectAccess with Windows Server 2016 Book

Deployment Considerations for DirectAccess on Amazon Web Services (AWS)

Organizations are rapidly deploying Windows server infrastructure with public cloud providers such as Amazon Web Services (AWS) and Microsoft Azure. With traditional on-premises infrastructure now hosted in the cloud, DirectAccess is also being deployed there more commonly.

Supportability

Interestingly, Microsoft has expressly stated that DirectAccess is not formally supported on their own public cloud platform, Azure. However, there is no formal statement of non-support for DirectAccess hosted on other non-Microsoft public cloud platforms. With supportability for DirectAccess on AWS unclear, many companies are taking the approach that if it isn’t unsupported, then it must be supported. I’d suggest proceeding with caution, as Microsoft could issue formal guidance to the contrary in the future.

DirectAccess on AWS

Deploying DirectAccess on AWS is similar to deploying on premises, with a few notable exceptions, outlined below.

IP Addressing

It is recommended that an IP address be exclusively assigned to the DirectAccess server in AWS, as shown here.

Deployment Considerations for DirectAccess on Amazon Web Services (AWS)

Prerequisites Check

When first configuring DirectAccess, the administrator will encounter the following warning message.

“The server does not comply with some DirectAccess prerequisites. Resolve all issues before proceed with DirectAccess deployment.”

The warning message itself states that “One or more network adapters should be configured with a static IP address. Obtain a static address and assign it to the adapter.

Deployment Considerations for DirectAccess on Amazon Web Services (AWS)

IP addressing for virtual machines are managed entirely by AWS. This means the DirectAccess server will have a DHCP-assigned address, even when an IP address is specified in AWS. Assigning static IP addresses in the guest virtual machine itself is also not supported. However, this warning message can safely be ignored.

No Support for Load Balancing

It is not possible to create load-balanced clusters of DirectAccess servers for redundancy or scalability on AWS. This is because enabling load balancing for DirectAccess requires the IP address of the DirectAccess server be changed in the operating system, which is not supported on AWS. To eliminate single points of failure in the DirectAccess architecture or to add additional capacity, multisite must be enabled. Each additional DirectAccess server must be provisioned as an individual entry point.

Network Topology

DirectAccess servers on AWS can be provisioned with one or two network interfaces. Using two network interfaces is recommended, with the external network interface of the DirectAccess server residing in a dedicated perimeter/DMZ network. The external network interface must use either the Public or Private Windows firewall profile. DirectAccess will not work if the external interface uses the Domain profile. For the Public and Private profile to be enabled, domain controllers must not be reachable from the perimeter/DMZ network. Ensure the perimeter/DMZ network cannot access the internal network by restricting network access in EC2 using a Security Group, or on the VPC using a Network Access Control List (ACL) or custom route table settings.

External Connectivity

A public IPv4 address must be associated with the DirectAccess server in AWS. There are several ways to accomplish this. The simplest way is to assign a public IPv4 address to the virtual machine (VM). However, a public IP address can only be assigned to the VM when it is deployed initially and cannot be added later. Alternatively, an Elastic IP can be provisioned and assigned to the DirectAccess server at any time.

An ACL must also be configured for the public IP that restricts access from the Internet to only inbound TCP port 443. To provide additional protection, consider deploying an Application Delivery Controller (ADC) appliance like the Citrix NetScaler or F5 BIG-IP to enforce client certificate authentication for DirectAccess clients.

Network Location Server (NLS)

If an organization is hosting all of its Windows infrastructure in AWS and all clients will be remote, Network Location Server (NLS) availability becomes much less critical than with traditional on-premises deployments. For cloud-only deployments, hosting the NLS on the DirectAccess server is a viable option. It eliminates the need for dedicated NLS, reducing costs and administrative overhead. If multisite is configured, ensure that the NLS is not using a self-signed certificate, as this is unsupported.

Deployment Considerations for DirectAccess on Amazon Web Services (AWS)

However, for hybrid cloud deployments where on-premises DirectAccess clients share the same internal network with cloud-hosted DirectAccess servers, it is recommended that the NLS be deployed on dedicated, highly available servers following the guidance outlined here and here.

Client Provisioning

All supported DirectAccess clients will work with DirectAccess on AWS. If the domain infrastructure is hosted exclusively in AWS, provisioning clients can be performed using Offline Domain Join (ODJ). Provisioning DirectAccess clients using ODJ is only supported in Windows 8.x/10. Windows 7 clients cannot be provisioned using ODJ and must be joined to the domain using another form of remote network connectivity such as VPN.

Additional Resources

DirectAccess No Longer Supported in Microsoft Azure

Microsoft Server Software Support for Azure Virtual Machines

DirectAccess Network Location Server (NLS) Guidance

DirectAccess Network Location Server (NLS) Deployment Considerations for Large Enterprises

Provisioning DirectAccess Clients using Offline Domain Join (ODJ)

DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler

DirectAccess SSL Offload and IP-HTTPS Preauthentication with F5 BIG-IP

Planning and Implementing DirectAccess with Windows Server 2016 Video Training Course

Implementing DirectAccess with Windows Server 2016 Book

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

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

Planning and Implementing DirectAccess with Windows Server 2016I’m excited to announce my latest video training course, Planning and Implementing DirectAccess with Windows Server 2016, is now available on Pluralsight! In this course, I’ll provide a high-level overview of DirectAccess, compare it with VPN, and outline supporting infrastructure requirements. In addition, you’ll learn how to choose the best network topology for a DirectAccess deployment, how to prepare Active Directory and Public Key Infrastructure (PKI) for DirectAccess, and how to install and configure DirectAccess in Windows Server 2016 using the latest implementation and security best practices. You’ll also learn how to provision Windows 10 clients and understand the unique requirements for supporting Windows 7.

The course includes the following training modules:

Overview of DirectAccess
Planning for DirectAccess
Configuring DirectAccess with the Getting Started Wizard
Configuring DirectAccess with the Remote Access Setup Wizard
Provisioning DirectAccess Clients
Supporting Windows 7 Clients

Throughout the course, I share valuable knowledge and insight gained from more than 5 years of experience deploying DirectAccess for some of the largest organizations in the world. Pluralsight offers a free trial subscription if you don’t already have one, so watch my DirectAccess video training course today!

Additional Resources

Planning and Implementing DirectAccess with Windows Server 2016 on Pluralsight
Implementing DirectAccess with Windows Server 2016

DirectAccess IPv6 Support for WorkSite and iManage Work

DirectAccess IPv6 Support for WorkSite and iManage WorkiManage Work (formerly WorkSite) is a popular document management system commonly used in the legal, accounting, and financial services industries. Historically, there have been issues getting WorkSite to function over DirectAccess, because WorkSite used IPv4 addresses and DirectAccess clients use IPv6. When a DirectAccess client is outside of the office, it communicates with the DirectAccess server using IPv6 exclusively, so applications that make calls directly to IPv4 addresses won’t work.

One way DirectAccess administrators could make WorkSite function was to use portproxy to create v4tov6 address and port mappings on the client. However, this method is error prone, difficult to troubleshoot and support, and doesn’t scale effectively.

The good news is that beginning with release 9, the iManage Work client application has been upgraded to support IPv6. However, it is not enabled by default. To enable IPv6 support for iManage Work, add the following registry key on the client side (not the server!). No other changes are required.

HKLM\Software\Wow6432Node\Interwoven\WorkSite\Server Common\

Type: REG_SZ
String: IP Address Family
Value: IPv6

DirectAccess IPv6 Support for WorkSite and iManage Work

You can also use the following PowerShell command to add this registry entry.

New-Item -Path “HKLM:\Software\Wow6432Node\Interwoven\WorkSite\Server Common\” -Force
New-ItemProperty -Path “HKLM:\Software\Wow6432Node\Interwoven\WorkSite\Server Common\”-Name “IP Address Family” -PropertyType String -Value IPv6 -Force

After validation testing is complete, deploy the registry setting via Active Directory group policy preferences to all DirectAccess clients and iManage Work will function perfectly over DirectAccess!

Additional Resources

Active Directory Group Policy Preferences on Microsoft TechNet

iManage Web Site

Implementing DirectAccess with Windows Server 2016

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