DirectAccess IP-HTTPS Error 0x2af9

When troubleshooting DirectAccess client connectivity issues, you may encounter a scenario where clients are unable to connect using the IP-HTTPS IPv6 transition technology. Running ipconfig shows that the tunnel adapter IPHTTPSInterface media state is Media disconnected.

DirectAccess IP-HTTPS Error 0x2af9

Running the Get-NetIpHttpsState PowerShell command shows that the LastErrorCode is 0x2af9 (WSAHOST_NOT_FOUND) and the InterfaceStatus is Failed to connect to the IPHTTPS server; waiting to reconnect.

DirectAccess IP-HTTPS Error 0x2af9

The 0x2af9 error differs slightly from the more common 0x274c IP-HTTPS connection time out error (WSAETIMEDOUT). In this scenario the DirectAccess client can successfully resolve the DirectAccess public hostname to an IPv4 address, and if ICMP echo requests are allowed on the DirectAccess server’s public IPv4 address it will respond to ping.

DirectAccess IP-HTTPS Error 0x2af9

The DirectAccess client is also able to establish a TCP connection to the DirectAccess server using the Test-NetConnection PowerShell command.

DirectAccess IP-HTTPS Error 0x2af9

So, why is the IP-HTTPS interface unable to establish a transition tunnel connection when the DirectAccess server’s public hostname resolves correctly via DNS and the client can establish a TCP connection on port 443? Commonly this is caused by proxy server settings configured in the web browser on the DirectAccess client computer. Disabling the proxy server in the client’s web browser should restore DirectAccess client connectivity over IP-HTTPS.

DirectAccess IP-HTTPS Error 0x2af9

If clearing the proxy server settings in the client machine’s web browser still does not restore IP-HTTPS connectivity, it may be that a proxy server is also configured for winhttp. You can confirm this by opening an elevated PowerShell command window and running the netsh winhttp show proxy command.

DirectAccess IP-HTTPS Error 0x2af9

To clear the winhttp proxy server settings run the netsh winhttp reset proxy command.

DirectAccess IP-HTTPS Error 0x2af9

Additional Resources

DirectAccess Expired IP-HTTPS Certificate and Error 0x800b0101

DirectAccess IP-HTTPS Preauthentication

DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler

DirectAccess SSL Offload using F5 BIG-IP

DirectAccess IP-HTTPS Preauthentication with F5 BIG-IP

DirectAccess and Multi-SAN SSL Certificates for IP-HTTPS

Implementing DirectAccess with Windows Server 2016 Book

 

DirectAccess Expired IP-HTTPS Certificate and Error 0x800b0101

Introduction

DirectAccess is an IPv6 only solution, at least from the perspective of the client. When the DirectAccess client is remote, it communicates with the DirectAccess server using IPv6 exclusively. IPv6 transition technologies are used to enable this connectivity when the DirectAccess server and/or client are on the pubic IPv4 Internet.

IP-HTTPS

One of the IPv6 transition technologies used by DirectAccess is IP-HTTPS. With IP-HTTPS, IPv6 traffic is encapsulated in HTTP and delivered to the DirectAccess server using IPv4. IP-HTTPS is used exclusively when the DirectAccess server is located behind an edge firewall performing network address translation.

SSL Certificate

To support IP-HTTPS, an SSL certificate is installed on each DirectAccess server. The SSL certificate is commonly issued by a public certification authority, but it can also be issued by an internal PKI. The SSL certificate used for IP-HTTPS can and does expire, and when it does it will prevent any DirectAccess connection from being established using this transition technology.

Troubleshooting

When troubleshooting DirectAccess connectivity via IP-HTTPS, the first thing the administrator will notice is that the media state for the DirectAccess client’s IP-HTTPS tunnel adapter interface is shown as disconnected.

DirectAccess Expired IP-HTTPS Certificate and Error 0x800b0101

In addition, the Get-NetIPHttpsState PowerShell command returns an error code 0x800b0101 indicating Failed to connect to the IP-HTTPS server; waiting to reconnect.

DirectAccess Expired IP-HTTPS Certificate and Error 0x800b0101

Err.exe translates this error to CERT_E_EXPIRED, indicating that the SSL certificate is no longer valid.

DirectAccess Expired IP-HTTPS Certificate and Error 0x800b0101

Viewing the IP-HTTPS SSL certificate is not possible using a web browser. Instead, use Nmap and the ssl-cert script to view the certificate.

nmap.exe -n -Pn -p443 [FQDN] –script ssl-cert

DirectAccess Expired IP-HTTPS Certificate and Error 0x800b0101

In the Operations Status window of the Remote Access Management console on the DirectAccess server, the IP-HTTPS status is listed as Critical. Details show IP-HTTPS not working properly, with an error stating the IP-HTTPS certificate is not valid, and clearly indicating that the certificate is expired.

DirectAccess Expired IP-HTTPS Certificate and Error 0x800b0101

The IP-HTTPS status can also be viewed at the command line by issuing the following command in an elevated PowerShell command window.

Get-RemoteAccessHealth | Where-Object Component -eq IP-Https | Format-List

DirectAccess Expired IP-HTTPS Certificate and Error 0x800b0101

Updating the Certificate

Simply renewing the SSL certificate is not sufficient to restore IP-HTTPS connectivity for remote DirectAccess clients. The DirectAccess configuration must also be updated to use the new certificate. In the Remote Access Management console, highlight DirectAccess and VPN under Configuration and then click Edit on Step 2 (for load-balanced or multisite DirectAccess deployments, first highlight the individual server and then click Configure Server Settings). Click Network Adapters, click Browse, and then select the new SSL certificate.

DirectAccess Expired IP-HTTPS Certificate and Error 0x800b0101

Click Ok, Next, and then Finish twice and Apply. Repeat these steps for each server in the load-balanced cluster, and for all servers in all entry points in the enterprise.

Alternatively, the IP-HTTPS certificate can be updated in the DirectAccess configuration by opening an elevated PowerShell command window and entering the following commands.

$cert = Get-ChildItem -Path cert:\localmachine\my | Where-Object Thumbprint -eq [cert_thumbprint]
Set-RemoteAccess -SslCertificate $cert -Verbose

For example…

$cert = Get-ChildItem -Path cert:\localmachine\my | Where-Object Thumbprint -eq 2BFD1BC5805EBBF8ACB584DA025AD75B341A8B33
Set-RemoteAccess -SslCertificate $cert -Verbose


Important Note: Be sure to execute these commands on each DirectAccess server in the load-balanced cluster, and for all servers in all entry points in the enterprise.


Self-Signed Certificates

When DirectAccess is deployed using the Getting Started Wizard (GSW), also known as a “simplified deployment“, a self-signed certificate is used for IP-HTTPS. By default, this certificate expires 5 years after it is created. The expiration of a self-signed certificate presentsa unique challenge. Although the self-signed certificate can’t be renewed, it can be re-created or cloned using the New-SelfSignedCertificate PowerShell command. However, DirectAccess clients will not trust this new certificate until they receive the updated client settings via group policy. DirectAccess clients outside the network will not be able to establish IP-HTTPS connections until they receive these new policies. When they attempt to connect to the DirectAccess server without first updating group policy, the IP-HTTPS status will indicate an error code 0x800b0109 which translates to CERT_E_UNTRUSTEDROOT.

If the expired self-signed certificate is replaced with another self-signed certificate (not recommended), DirectAccess clients will have to come back to the internal network or connect remotely via client-based VPN to update group policy and receive the new DirectAccess client settings. A better alternative is to replace the expired self-signed certificate with a public SSL certificate that matches the existing public hostname. This will allow remote clients to reestablish DirectAccess connectivity without the need to udpate group policy first.

Summary

Certificate expiration must be monitored closely to ensure the highest level of availability for the DirectAccess remote access solution. Certificate auto enrollment can be leveraged to ensure that IPsec certificates are automatically renewed prior to expiration. However, the IP-HTTPS certificate must be renewed manually and requires additional configuration after it has been updated.

Additional Resources

DirectAccess Computer Certificate Auto Enrollment

DirectAccess and Multi-SAN SSL Certificates for IP-HTTPS

Implementing DirectAccess with Windows Server 2016 book

DirectAccess IP-HTTPS Preauthentication


Introduction

DirectAccess IP-HTTPS PreauthenticationRecently I’ve written about the security challenges with DirectAccess, specifically around the use of the IP-HTTPS IPv6 transition technology. In its default configuration, the DirectAccess server does not authenticate the client when an IP-HTTPS transition tunnel is established. This opens up the possibility of an unauthorized user launching Denial-of-Service (DoS) attacks and potentially performing network reconnaissance using ICMPv6. More details on this can be found here.

Mitigation

The best way to mitigate these security risks is to implement an Application Delivery Controller (ADC) such as the F5 BIG-IP Local Traffic Manager or the Citrix NetScaler. I’ve documented how to configure those platforms here and here.

No ADC?

For those organizations that do not have a capable ADC deployed, it is possible to configure the IP-HTTPS listener on the Windows Server 2012 R2 server itself to perform preauthentication.

Important Note: Making the following changes on the DirectAccess server is not formally supported. Also, this change is incompatible with one-time passwords (OTP)  and should not be performed if strong user authentication is enabled. In addition, null cipher suites will be disabled, resulting in reduced scalability and degraded performance for Windows 8.x and Windows 10 clients. Making this change should only be done if a suitable ADC is not available.

Configure IP-HTTPS Preauthentication

To configure the DirectAccess server to perform preauthentication for IP-HTTPS connections, open an elevated PowerShell command window and enter the following command.

ls Cert:\LocalMachine\My

DirectAccess IP-HTTPS Preauthentication

Copy the thumbprint that belongs to the SSL certificate assigned to the IP-HTTPS listener. Open an elevated command prompt window (not a PowerShell window!) and enter the following commands.

netsh http delete sslcert ipport=0.0.0.0:443
netsh http add sslcert ipport=0.0.0.0:443 certhash=[thumbprint]
appid={5d8e2743-ef20-4d38-8751-7e400f200e65}
dsmapperusage=enable clientcertnegotiation=enable

DirectAccess IP-HTTPS Preauthentication

For load-balanced clusters and multisite deployments, repeat these steps on each DirectAccess server in the cluster and/or enterprise.

Summary

Once these changes have been made, only DirectAccess clients that have a computer certificate with a subject name that matches the name of its computer account in Active Directory will be allowed to establish an IP-HTTPS transition tunnel connection.

DirectAccess and Windows 10 in Action

DirectAccess and Windows 10 in ActionRecently I recorded a short video to outline some of the benefits of using Windows 10 and DirectAccess. The video highlights common uses cases and includes a working demonstration of DirectAccess and Windows 10, both from the user’s and the administrator’s perspective.

The video shows how users transparently connect to the network and seamlessly access corporate resources over the DirectAccess connection. It also shows how administrators can leverage existing system management tools such as the Computer Management MMC, PowerShell remoting, and the Remote Desktop Protocol (RDP) to manage remote connected Windows 10 DirectAccess clients.

If you have any questions about implementing DirectAccess, integrating Windows 10 clients, or enabling outbound management, click here.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Introduction

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic ManagerTo provide geographic redundancy, DirectAccess can be deployed in a multisite configuration. In this scenario, Windows 8.x and Windows 10 clients are aware of all entry points in the enterprise and will automatically select the nearest available entry point to connect to. The nearest entry point is defined as the one that responds the quickest. When a Windows 8.x or Windows 10 client attempts to establish DirectAccess connectivity, an HTTP GET is sent to all entry points and the client will select the one with the shortest Round Trip Time (RTT) for the request.

Note: Windows 7 clients can be provisioned when DirectAccess is configured for multisite access, but they must be assigned to an individual entry point.

Challenges

There are a number of challenges that come with the default multisite configuration. Choosing an entry point based solely on network latency is rather simplistic and can often produce unexpected results. It also lacks support for granular traffic distribution or active/passive configuration.

GSLB

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic ManagerFor the best experience, DirectAccess can be configured to use a Global Server Load Balancing (GSLB) solution to enhance transparent site selection and failover for Windows 8.x and Windows 10 clients. Commonly this is implemented using an on-premises appliance (Citrix NetScaler, F5 Global Traffic Manager, Kemp LoadMaster, A10 Thunder, etc.). These solutions offer exceptional control over DirectAccess traffic distribution, but they add expense and complexity.

Azure Traffic Manager

Azure Traffic Manager is a cloud-based GSLB solution that is a simple and cost-effective alternative to dedicated on-premises appliances. While it does not offer all of the features that GSLB appliances provide, it does provide better traffic distribution options than the default configuration. Importantly, it enables active/passive failover, which is a common requirement not supported natively with DirectAccess.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Traffic Manager Configuration

In the Azure portal (the new one, not the old one!) click New, Networking, and then Traffic Manager profile.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Provide a name and select a Routing method.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Routing method options are Performance, Weighted and Priority.

  • Performance. Select this option to enable clients to connect to the entry point with the lowest network latency.
  • Weighted. Select this option to enable clients to prefer some entry points more than others. Assign a weight value of 1 to 1000 for each entry point. Higher values have more preference. Values for entry points can be the same, if desired.
  • Priority. Select this option to enable clients to connect to a primary entry point, then fail over to a secondary or tertiary entry point in the event of an outage. Assign a priority value of 1 to 1000 for each entry point. Lower values take precedence. Each entry point must be assigned a unique priority value.

Click Create when finished. Next click Settings for the new traffic manager profile and click Configuration. Change Protocol to HTTPS, Port to 443, and Path to /IPHTTPS. Click Save when finished.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Next click Endpoints and click Add. Select External endpoint from the drop down list, provide a descriptive name, and then enter the Fully-Qualified Domain Name (FQDN) of the first DirectAccess entry point. When using the Performance routing method, choose a location that best represents the geography where the DirectAccess entry point is located. When using the Weighted or Priority routing methods, specify an appropriate value accordingly. Click Ok when finished. Repeat these steps for each entry point in the organization.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

DirectAccess Configuration

In the Remote Access Management console, highlight DirectAccess and VPN below Configuration in the navigation tree and then click Configure Multisite Settings below Multisite Deployment in the Tasks pane. Click Global Load Balancing and choose Yes, use global load balancing. Enter the FQDN of the Azure Traffic Manager profile and click Next, and then click Commit.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Note: An SSL certificate with a subject name matching that of the GSLB FQDN is not required.

In some cases, the management console may report that global load balancing addresses cannot be identified automatically for some or all entry points.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

If this occurs, it will be necessary to run the Set-DAEntryPoint PowerShell cmdlet to assign GLSB IP addresses to each entry point. The GSLB IP address is the public IPv4 address that the entry point public hostname resolves to.

Set-DAEntryPoint -Name [entrypoint_name] -GslbIP [external_ip_address]

For example:

Set-DAEntryPoint -Name "US West" -GslbIP 203.0.113.195
Set-DAEntryPoint -Name "US East" -GslbIP 198.51.100.21

Summary

DirectAccess includes native functionality to enable geographic load balancing for Windows 8.x and Windows 10 clients. The site selection process used by DirectAccess clients in this scenario is basic, and has the potential to yield unexpected results. Azure Traffic Manager is a simple, cost-effective alternative to dedicated on-premises GSLB appliances. It can be integrated with DirectAccess to address some of the shortcomings with the native entry point selection process.

Additional Resources

DirectAccess Inbox Accounting Database Optimization

DirectAccess Inbox Accounting Database OptimizationRecently I wrote about an issue with DirectAccess servers exhibiting high SQL Server CPU usage. In that article I demonstrated a way to resolve the issue by adding a crucial index to a table in the remote access inbox accounting database. The process was a bit involved and required downloading third-party tools to make configuration changes on the DirectAccess server.

Going forward, making these changes will now be much easier. Microsoft has published guidance for optimizing the remote access inbox accounting database using PowerShell. They’ve also provided scripts to back up the database and to confirm that optimization has been implemented.

For more information and to download the remote access inbox accounting database optimization PowerShell scripts, click here.

DirectAccess and Windows Server 2012 R2 Core

Introduction

DirectAccess and Windows Server 2012 R2 Core

Windows Server Core is an operating system configuration option that does not include a Graphical User Interface (GUI). Server Core was first introduced with Windows Server 2008 and originally included only a limited number of supported roles. With each subsequent release, Microsoft continues to add support for additional roles on Server Core. Beginning with Windows Server 2012, the Routing and Remote Access (RRAS) role, which includes DirectAccess, is a supported workload on Server Core.

Advantages of Server Core

There are a number of important advantages that come with running DirectAccess on Server Core. Server Core has a greatly reduced attack surface compared to the full GUI version, which is positive from a security perspective. Server Core also features a dramatically reduced footprint, consuming less RAM and disk space. System startup times are faster, and this refactored installation option also reduces servicing requirements (patching), eliminating many reboots and increasing availability and overall system uptime.

DirectAccess and Windows Server 2012 R2 Core

Figure 1 – Windows Server 2012 R2 Core Desktop (Yes, that’s it!)

Server Core Configuration

DirectAccess is a workload that lends itself well to running on Server Core, and I highly recommend leveraging this configuration whenever possible. Based on my experience, I suggest performing initial configuration and testing of the DirectAccess solution with the GUI installed, and then removing the GUI just before placing the DirectAccess server in to production. Removing the GUI can be accomplished by executing the following PowerShell command:

Remove-WindowsFeature Server-Gui-Mgmt-Infra –Restart

Once the server has been converted to Server Core, all administration must be performed at the command line on the server, or remotely from a management server or workstation using the command line or GUI administration tools. You can install the Remote Access Management console on any Windows Server 2012 R2 server using the following PowerShell command:

Install-WindowsFeature RSAT-RemoteAccess

Optionally you can download and install the Windows Server Remote Administrations Tools (RSAT) on a Windows client workstation, if desired.

Minimal Server Interface Configuration

If you prefer to be able to manage the DirectAccess server locally using the GUI, consider enabling the Minimal Server Interface. Minimal Server Interface is a configuration option that lies between Server Core and the full GUI interface. It features some of the benefits of Server Core, while at the same time providing local access to GUI management tools such as the Remote Access Management console. You can configure Minimal Server Interface using the following PowerShell command:

Remove-WindowsFeature Server-Gui-Shell -Restart

You can access the Remote Access Management console by entering RaMgmtUI.exe from the command line.

Revert to Full GUI

If at any point in the future you require the GUI for some reason, re-installing it can be accomplished using the following PowerShell command:

Install-WindowsFeature Server-Gui-Shell –Restart

Summary

With the Unified Remote Access role supported on Windows Server Core, consider implementing DirectAccess using this option to improve the security and increase the availability of your remote access solution. You’ll find that almost all ongoing server maintenance and support can be accomplished remotely using GUI tools, or locally using PowerShell. And if you ever need the GUI again, you can always add it back if necessary!

Windows Clients Do Not Receive DirectAccess Configuration Changes

Windows Clients Do Not Receive DirectAccess Configuration Changes

A scenario can occur in which changes to the DirectAccess configuration made using the Remote Access Management console or at the command line using PowerShell are not reflected on the DirectAccess client, even after receiving the latest group policy updates. The issue occurs for DirectAccess clients that are provisioned with the Offline Domain Join (ODJ, or djoin.exe) tool.

When the ODJ provisioning package is initially created, it does not add the new computer account to the DirectAccess security group. The ODJ-provisioned client receives all DirectAccess configuration settings at the time of provisioning, but it will not receive subsequent changes to the DirectAccess configuration made after it was originally provisioned.

To resolve this issue, be sure to proactively add the DirectAccess client’s computer account to the appropriate DirectAccess security group in Active Directory after provisioning with ODJ using Active Directory Users and Computers (ADUC), the Active Directory Administrative Center (ADAC), or by executing the following PowerShell command:

Add-ADGroupMember -Identity [DirectAccess Client Security Group] -Members [computername]

Once the DirectAccess client has been added to the security group and restarted, it will then receive DirectAccess configuration settings changes going forward.

3 Important Things You Need to Know about Windows 10 and DirectAccess

DirectAccess and Windows 10 - Better TogetherDirectAccess has been with us for quite some time know, having been originally introduced with Windows Server 2008 R2, later enhanced with Forefront Unified Access Gateway (UAG) 2010, and finally integrated in to the base operating system in Windows Server 2012 R2. Client support for DirectAccess begins with Windows 7 (Enterprise or Ultimate), and also includes Windows 8.x (Enterprise) and Windows 10 (Enterprise or Education).

Although Windows 7 clients are supported for DirectAccess, Windows 10 is highly preferred. Here are three important things you need to know about using Windows 10 with DirectAccess.

  1. Windows 10 Provides Improved Performance and Scalability – Windows 10 includes support for null encryption when using the IP-HTTPS IPv6 transition protocol. This eliminates the needless double-encryption performed by Windows 7 clients, and dramatically reduces the protocol overhead for clients connecting behind port-restricted firewalls. DirectAccess servers can support many more concurrent IP-HTTPS sessions with Windows 10, and it has the added benefit of making the more secure perimeter/DMZ deployment behind an edge security device performing NAT much more attractive.
  2. Windows 10 Supports Geographic Redundancy – Windows 10 includes full support for DirectAccess multisite deployments. Where Windows 7 clients had to be assigned to a single entry point, Windows 10 clients are aware of all entry points in the organization. They are able to automatically select the nearest entry point on startup, and transparently failover to another site if the current site becomes unavailable.
  3. Windows 10 Features an Enhanced Management Experience – From a troubleshooting and support perspective, Windows 10 makes things much easier. The DirectAccess connectivity assistant, an optional component for Windows 7, is now fully integrated with the Windows 10 UI. PowerShell is greatly improved and now includes many native DirectAccess configuration and troubleshooting commands.

As you can see, there are a number of significant advantages for using Windows 10 with DirectAccess. Windows 10 now supports all of the enterprise features of DirectAccess, including geographic redundancy and performance and scalability improvements. Windows 10 is also easier to troubleshoot and manage. If you’re still supporting Windows 7, DirectAccess in Windows Server 2012 R2 can certainly support them. However, without a doubt the best experience, both from an administrator’s and the end user’s perspective, is with Windows 10. Just one more reason to begin planning your migration to Windows 10 with DirectAccess today!

Need assistance with implementing  DirectAccess with Windows 10? I can help! More details here.

DirectAccess Manage Out from Windows 10 Does Not Work

For DirectAccess manage out deployments using ISATAP, you may encounter a scenario in which you are unable to initiate outbound connections to connected DirectAccess clients from a Windows 10 computer. Outbound connections using ISATAP from Windows 7, Windows 8, Windows Server 2008/R2, or Windows Server 2012/R2 systems work without issue.

DirectAccess Manage Out from Windows 10 Does Not Work

As it turns out, there is a bug in the Windows 10 DNS client code that prevents manage out using ISATAP from a Windows 10 client from working correctly. Thanks to the diligent effort of DirectAccess administrators Mike Piron and Jason Kuhns, a workaround has been identified. To deploy the workaround, it will be necessary to implement registry changes to alter the default behavior of the DNS resolver in Windows 10. You can implement these changes on a Windows 10 DirectAccess manage out machine by using the following PowerShell commands:

New-ItemProperty -Path “HKLM:\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters\” -Name DisableParallelAandAAAA -PropertyType dword -Value 1 -Force

New-ItemProperty -Path “HKLM:\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters\” -Name DisableServerUnreachability -PropertyType dword -Value 1 –Force

Once these registry changes have been made, you should now be able to use ISATAP for DirectAccess manage out connections from a Windows 10 machine.

%d bloggers like this: