Always On VPN Client DNS Server Configuration

Always On VPN Client DNS Server ConfigurationDNS server configuration for Windows 10 Always On VPN clients is crucial to ensuring full access to internal resources. For Always On VPN, there are a few different ways to assign a DNS server to VPN clients.

Default DNS Servers

By default, Windows 10 clients use the same DNS server the VPN server is configured to use. This is true even if the VPN client IP address assignment method is DHCP.

Always On VPN Client DNS Server Configuration

There may be some scenarios in which this is not appropriate. For example, if the DNS server is in a DMZ network and is not configured to use internal Active Directory domain DNS servers, clients will be unable to access internal resources.

DNS Server Assignment

To configure Windows 10 Always On VPN clients to use DNS servers other than those configured on the VPN server, configure the DomainNameInformation element in the ProfileXML, as shown here.

<VPNProfile>
   <DomainNameInformation>
      <DomainName>.corp.example.net</DomainName>
      <DnsServers>10.21.12.100,10.21.12.101</DnsServers>
   </DomainNameInformation>
</VPNProfile>

Note: Be sure to include the lading “.” In the domain name to ensure that all hosts and subdomains are included.

Always On VPN Client DNS Server Configuration

Reference: https://docs.microsoft.com/en-us/windows/client-management/mdm/vpnv2-csp

Additional Information

Windows 10 Always On VPN and the Name Resolution Policy Table (NRPT)

Deploying Windows 10 Always On VPN with Microsoft Intune

Windows 10 Always On VPN Certificate Requirements for IKEv2

Windows 10 Always On VPN Hands-On Training

Always On VPN and the Name Resolution Policy Table (NRPT)

Always On VPN and the Name Resolution Policy Table (NRPT)The Name Resolution Policy Table (NRPT) is a function of the Windows client and server operating systems that allows administrators to enable policy-based name resolution request routing. Instead of sending all name resolution requests to the DNS server configured on the computer’s network adapter, the NRPT can be used to define unique DNS servers for specific namespaces.

DirectAccess administrators will be intimately familiar with the NRPT, as it is explicitly required for DirectAccess operation. Use of the NRPT for Windows 10 Always On VPN is optional, however. It is commonly used for deployments where split DNS is enabled. Here the NRPT can define DNS servers for the internal namespace, and exclusions can be configured for FQDNs that should not be routed over the VPN tunnel.

To enable the NRPT for Windows 10 Always On VPN, edit the ProfileXML to include the DomainNameInformation element.

<DomainNameInformation>
   <DomainName>.example.net</DomainName>
   <DnsServers>10.21.12.100,10.21.12.101</DnsServers>
</DomainNameInformation>

Note: Be sure to include the leading “.” in the domain name to ensure that all hosts and subdomains are included.

To create an NRPT exclusion simply omit the DnsServers element. Define additional entries for each hostname to be excluded, as shown here.

<DomainNameInformation>
   <DomainName>www.example.net</DomainName>
</DomainNameInformation>
<DomainNameInformation>
   <DomainName>mail.example.net</DomainName>
</DomainNameInformation>
<DomainNameInformation>
   <DomainName>autodiscover.example.net</DomainName>
</DomainNameInformation>

Additional Information

Windows 10 VPNv2 Configuration Service Provider (CSP) Reference

Windows 10 Always On VPN Protocol Recommendations for Windows Server Routing and Remote Access Services (RRAS)

Windows 10 Always On VPN Hands-On Training

Cloudflare Public DNS Resolver Now Available

Cloudflare Public DNS Resolver Now AvailableCloudflare has become a nearly ubiquitous cloud service provider in recent years, fronting many of the busiest web sites on the Internet. They provide tremendous value both in terms of security and performance for their customers. They have a wide array of solutions designed to provide better security, including optimized SSL/TLS configuration and Web Application Firewall (WAF) capabilities. Their DDoS mitigation service is second to none, and their robust Content Delivery Network (CDN) ensures optimal loading of content for web sites anywhere in the world.

Public DNS Resolver

Recently Cloudflare announced their first consumer service, a public DNS resolver that is free for general use. It offers exceptional performance and supports many of the latest DNS security and privacy enhancements such as DNS-over-TLS. Cloudflare has also pledged not to write DNS queries to disk at all and not to store them for more than 24 hours to further ensure privacy for their customers.

Cloudflare Public DNS Resolver Now Available

DNS Security Controls

What Cloudflare DNS is lacking today is granular security enforcement to provide additional protection for client computers outside the firewall. For example, public DNS resolvers from OpenDNS and Quad9 have built-in security features that use threat intelligence to identify and block DNS name resolution requests for domains that are known to be malicious or unsafe. OpenDNS has the added benefit of providing more granularity for setting policy, allowing administrators to select different filtering levels and optionally to create custom policies to allow or block individually selected categories. With OpenDNS, security administrators can also manage domains individually by manually assigning allow or block to specific, individual domains as necessary.

Recommended Use Cases

Cloudflare DNS clearly offers the best performance of all public DNS resolvers today, which makes it a good candidate for servers that rely heavily on DNS for operation. Mail servers come to mind immediately, but any system that performs many forward and/or reverse DNS lookups would benefit from using Cloudflare DNS. Cloudflare DNS can also be used by client machines where better performance and enhanced privacy are desired.

Quad9 DNS is a good choice for client computers where additional security is required. OpenDNS is the best choice where the highest level of security is required, and where granular control of security and web filtering policies is necessary.

Additional Information

Cloudflare DNS
Quad9 DNS
OpenDNS
Dnsperf.com

DirectAccess NRPT Configuration with Split DNS

DirectAccess NRPT Configuration with Split DNSThe Name Resolution Policy Table (NRPT) in Windows provides policy-based name resolution request routing for DNS queries. DirectAccess uses the NRPT to ensure that only requests for resources in the internal namespace, as defined by the DirectAccess administrator, are sent over the DirectAccess connection. DNS queries for all other namespaces are sent to the DNS servers defined on the client’s network interface.

Note: This behavior changes when force tunneling is enabled. In this case, all DNS queries are sent over the DirectAccess connection with the exception of the NLS and the DirectAccess server’s public hostname(s). If force tunneling is enabled, the configuration guidance described below is not required.

Split DNS

NRPT configuration is straightforward when the internal and external namespaces are unique. However, when split DNS is used, meaning when the internal and external namespaces are the same, DirectAccess configuration is more challenging. Typically, there may be many resources that should not go over the DirectAccess connection, such as public-facing web servers, email and unified communications servers, federation servers, etc. Without additional configuration, requests for all of these services would go over the DirectAccess connection. That may or may not be desirable, depending on the requirements of the implementation.

DirectAccess Server

One crucial public resource is the DirectAccess server itself. When using split DNS, the DirectAccess implementation’s public hostname will, by default, be included in the internal namespace. In this scenario, the DirectAccess client will fail to establish a connection to the DirectAccess server.

Troubleshooting

When troubleshooting failed connectivity, the output of ipconfig will show the IP-HTTPS tunnel interface media state as “Media disconnected”.

DirectAccess NRPT Configuration with Split DNS

The output of Get-NetIPHttpsState will also return an error code 0x2AF9 with an interface status “Failed to connect to the IPHTTPS server; waiting to reconnect”.

DirectAccess NRPT Configuration with Split DNS

To further troubleshoot this issue, examine the output of Get-NetIPHttpsConfiguration. Test name resolution of the FQDN listed in the ServerURL field. If the issue is related to NRPT configuration, the client will fail to resolve this name to an IP address. Testing from a non-DirectAccess client should resolve correctly, however.

DirectAccess NRPT Configuration with Split DNS

NRPT Configuration

If split DNS is employed, it is necessary to include the DirectAccess server’s public hostname in the NRPT as an exemption. This will cause the DNS query for the public hostname to use public DNS servers, allowing the DirectAccess client to establish a connection successfully.

To resolve this issue, open the Remote Access Management console on the DirectAccess server, highlight DirectAccess and VPN under Configuration, and then click Edit on Step 3. Select DNS, and then double-click on an empty row in the table.

DirectAccess NRPT Configuration with Split DNS

Enter the public hostname for the DirectAccess deployment in the DNS suffix field (the public hostname can be found by clicking Edit on Step 2). Do NOT specify a DNS server. Click Apply, click Next twice, and then click Finish.

DirectAccess NRPT Configuration with Split DNS

Note: For multisite deployments, be sure to include the public hostname for each entry point in the enterprise. Also, if multisite is configured to use GSLB, include the GSLB hostname as well.

PowerShell

Alternatively, you can run the following PowerShell commands to automatically configure the NRPT for split DNS. For multisite deployments, be sure to run these commands on at least one DirectAccess server in each site.

$hostname = Get-RemoteAccess | Select-Object -ExpandProperty ConnectToAddress
Add-DAClientDnsConfiguration -DnsSuffix $hostname -PassThru

If multisite is configured to use GSLB, run the following PowerShell commands on one DirectAccess server in the enterprise.

$gslbfqdn = Get-DAMultiSite | Select-Object -ExpandProperty GslbFqdn
Add-DAClientDnsConfiguration -DnsSuffix $gslbfqdn -PassThru

Additional Information

Troubleshooting DirectAccess IP-HTTPS Error 0x2af9

DirectAccess DNS Not Working Properly

DirectAccess DNS Records Explained

Troubleshooting Name Resolution Issue on DirectAccess Clients

DirectAccess Manage Out with ISATAP and NLB Clustering

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

ISATAP Supportability

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

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

ISATAP Configuration

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

DirectAccess Manage Out with ISATAP and NLB Clustering

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

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

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

DirectAccess Manage Out with ISATAP and NLB Clustering

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

DirectAccess Manage Out with ISATAP and NLB Clustering

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

DirectAccess Manage Out with ISATAP and NLB Clustering

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

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

Group Policy Deployment

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

DirectAccess Client Firewall Configuration

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

ISATAP Manage Out for Multisite and ELB

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

Summary

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

Additional Information

ISATAP Recommendations for DirectAccess Deployments

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

DirectAccess Client Firewall Rule Configuration for ISATAP Manage Out

DirectAccess Manage Out and System Center Configuration Manager (SCCM)

Contact Me

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

TechMentor Conference Orlando 2017

I'm Speaking at Live!360 and TechMentor Event 2017 in Orlando, Florida November 12-17. Join me!I’m pleased to announce that I’ll be speaking at the TechMentor Conference (which is part of Live! 360) in Orlando, FL. The event takes place November 12-17 and I will be delivering several sessions on DirectAccess, DNS policies, and network troubleshooting in Windows Server 2016. More details these sessions can be found here.

TMT02 – Implementing DirectAccess with Windows Server 2016

TMW01 – Network Troubleshooting for Windows Administrators

TMW04 – Introducing DNS Policies in Windows Server 2016

Sign up using promotion code LSPK34 and save $500.00. Register now!

 

 

Uninstalling and Removing DirectAccess

Uninstalling and Removing DirectAccess This web site is primarily dedicated to installing, configuring, managing, and troubleshooting DirectAccess on Windows Server 2012 R2 and Windows Server 2016. However, there’s little documentation on how to properly uninstall and remove DirectAccess. This post provides guidance for gracefully uninstalling and removing DirectAccess after it has been deployed.

DirectAccess Clients

It is recommended that all clients be deprovisioned prior to decommissioning a DirectAccess deployment. This is especially true if the Network Location Server (NLS) is hosted on the DirectAccess server itself. Remove all client computers from the DirectAccess client security group or unlink DirectAccess client settings GPOs (but don’t delete them!) from any OUs where they are applied. Allow sufficient time for all clients to process security group membership changes and update group policy before uninstalling DirectAccess.

Network Location Server

If the NLS is installed separate from the DirectAccess server, it is recommended that it remain online for a period of time after DirectAccess has been decommissioned. Clients will be unable to access local resources if they still have DirectAccess client settings applied and the NLS is offline. Keeping the NLS online prevents this from happening. If this does happen, you’ll need to delete the Name Resolution Policy Table (NRPT) on the client to restore connectivity. To do this, run the following command in an elevated PowerShell command window and restart the computer.

Get-Item -Path “HKLM:\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient\DnsPolicyConfig” | Remove-Item -Confirm:$false

Uninstall DirectAccess

It is not recommended to decommission DirectAccess by simply turning off all DirectAccess servers and manually deleting all of the associated group policy objects (GPOs) in Active Directory. A better way is to gracefully remove DirectAccess using the GUI or PowerShell.

To uninstall DirectAccess using the GUI, open the Remote Access Management console, highlight DirectAccess and VPN, and then click Remove Configuration Settings in the Tasks pane.

Uninstalling and Removing DirectAccess

Alternatively, DirectAccess can be removed by running the following command in an elevated PowerShell command window.

Uninstall-RemoteAccess -Force

Additional Resources

DirectAccess Network Location Server (NLS) Guidance

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

Implementing DirectAccess with Windows Server 2016

Deploying DirectAccess in Microsoft Azure

Introduction

DirectAccess Now a Supported Workload in Microsoft AzureMany organizations are preparing to implement DirectAccess on Microsoft’s public cloud infrastructure. Deploying DirectAccess in Azure is fundamentally no different than implementing it on premises, with a few important exceptions (see below). This article provides essential guidance for administrators to configure this unique workload in Azure.

Important Note: There has been much confusion regarding the supportability of DirectAccess in Azure. Historically it has not been supported. Recently, it appeared briefly that Microsoft reversed their earlier decision and was in fact going to support it. However, the Microsoft Server Software Suport for Microsoft Azure Virtual Machines document has once again been revised to indicate that DirectAccess is indeed no longer formally supported on Azure. More details can be found here.

Azure Configuration

The following is guidance for configuring network interfaces, IP address assignments, public DNS, and network security groups for deploying DirectAccess in Azure.

Virtual Machine

Deploy a virtual machine in Azure with sufficient resources to meet expected demand. A minimum of two CPU cores should be provisioned. A VM with 4 cores is recommended. Premium storage on SSD is optional, as DirectAccess is not a disk intensive workload.

Network Interfaces

It is recommended that an Azure VM with a single network interface be provisioned for the DirectAccess role. This differs from on-premises deployments where two network interfaces are preferred because deploying VMs in Azure with two NICs is prohibitively difficult. At the time of this writing, Azure VMs with multiple network interfaces can only be provisioned using PowerShell, Azure CLI, or resource manager templates. In addition, Azure VMs with multiple NICs cannot belong to the same resource group as other VMs. Finally, and perhaps most importantly, not all Azure VMs support multiple NICs.

Internal IP Address

Static IP address assignment is recommended for the DirectAccess VM in Azure. By default, Azure VMs are initially provisioned using dynamic IP addresses, so this change must be made after the VM has been provisioned. To assign a static internal IP address to an Azure VM, open the Azure management portal and perform the following steps:

  1. Click Virtual machines.
  2. Select the DirectAccess server VM.
  3. Click Network Interfaces.
  4. Click on the network interface assigned to the VM.
  5. Under Settings click IP configurations.
  6. Click Ipconfig1.
  7. In the Private IP address settings section choose Static for the assignment method.
  8. Enter an IP address for the VM.
  9. Click Save.

Deploying DirectAccess in Microsoft Azure

Public IP Address

The DirectAccess VM in Azure must have a public IP address assigned to it to allow remote client connectivity. To assign a public IP address to an Azure VM, open the Azure management portal and perform the following steps:

  1. Click Virtual machines.
  2. Select the DirectAccess server VM.
  3. Click Network Interfaces.
  4. Click on the network interface assigned to the VM.
  5. Under Settings click IP configurations.
  6. Click Ipconfig1.
  7. In the Public IP address settings section click Enabled.
  8. Click Configure required settings.
  9. Click Create New and provide a descriptive name for the public IP address.
  10. Choose an address assignment method.
  11. Click Ok and Save.

Deploying DirectAccess in Microsoft Azure

Deploying DirectAccess in Microsoft Azure

Public DNS

If the static IP address assignment method was chosen for the public IP address, create an A resource record in public DNS that resolves to this address. If the dynamic IP address assignment method was chosen, create a CNAME record in public DNS that maps to the public hostname for the DirectAccess server. To assign a public hostname to the VM in Azure, open the Azure management portal and perform the following steps:

  1. Click Virtual machines.
  2. Select the DirectAccess server VM.
  3. Click Overview.
  4. Click Public IP address/DNS name label.Deploying DirectAccess in Microsoft Azure
  5. Under Settings click Configuration.
  6. Choose an assignment method (static or dynamic).
  7. Enter a DNS name label.
  8. Click Save.

Deploying DirectAccess in Microsoft Azure

Note: The subject of the SSL certificate used for the DirectAccess IP-HTTPS listener must match the name of the public DNS record (A or CNAME) entered previously. The SSL certificate does not need to match the Azure DNS name label entered here.

Network Security Group

A network security group must be configured to allow IP-HTTPS traffic inbound to the DirectAccess server on the public IP address. To make the required changes to the network security group, open the Azure management portal and perform the following steps:

  1. Click Virtual machines.
  2. Select the DirectAccess server VM.
  3. Click Network interfaces.
  4. Click on the network interface assigned to the VM.
  5. Under Settings click Network security group.
  6. Click the network security group assigned to the network interface.
  7. Click Inbound security rules.
  8. Click Add and provide a descriptive name for the new rule.
  9. Click Any for Source.
  10. From the Service drop-down list choose HTTPS.
  11. Click Allow for Action.
  12. Click Ok.

Deploying DirectAccess in Microsoft Azure

Note: It is recommended that the default-allow-rdp rule be removed if it is not needed. At a minimum, scope the rule to allow RDP only from trusted hosts and/or networks.

DirectAccess Configuration

When performing the initial configuration of DirectAccess using the Remote Access Management console, the administrator will encounter the following warning message.

“One or more network adapters should be configured with a static IP address. Obtain a static address and assign it to the adapter.”

Deploying DirectAccess in Microsoft Azure

This message can safely be ignored because Azure infrastructure handles all IP address assignment for hosted VMs.

The public name of the DirectAccess server entered in the Remote Access Management console must resolve to the public IP address assigned to the Azure VM, as described previously.

Deploying DirectAccess in Microsoft Azure

Additional Considerations

When deploying DirectAccess in Azure, the following limitations should be considered.

Load Balancing

It is not possible to enable load balancing using Windows Network Load Balancing (NLB) or an external load balancer. Enabling load balancing for DirectAccess requires changing static IP address assignments in the Windows operating system directly, which is not supported in Azure. This is because IP addresses are assigned dynamically in Azure, even when the option to use static IP address assignment is chosen in the Azure management portal. Static IP address assignment for Azure virtual machines are functionally similar to using DHCP reservations on premises.

Deploying DirectAccess in Microsoft Azure

Note: Technically speaking, the DirectAccess server in Azure could be placed behind a third-party external load balancer for the purposes of performing SSL offload or IP-HTTPS preauthentication, as outlined here and here. However, load balancing cannot be enabled in the Remote Access Management console and only a single DirectAccess server per entry point can be deployed.

Manage Out

DirectAccess manage out using native IPv6 or ISATAP is not supported in Azure. At the time of this writing, Azure does not support IPv6 addressing for Azure VMs. In addition, ISATAP does not work due to limitations imposed by the underlying Azure network infrastructure.

Summary

For organizations moving infrastructure to Microsoft’s public cloud, formal support for the DirectAccess workload in Azure is welcome news. Implementing DirectAccess in Azure is similar to on-premises with a few crucial limitations. By following the guidelines outlined in this article, administrators can configure DirectAccess in Azure to meet their secure remote access needs with a minimum of trouble.

Additional Resources

Implementing DirectAccess in Windows Server 2016
Fundamentals of Microsoft Azure 2nd Edition
Microsoft Azure Security Infrastructure
DirectAccess Multisite with Azure Traffic Manager
DirectAccess Consulting Services

SSH Administration over a DirectAccess Connection

SSH Administration over a DirectAccess ConnectionFrom a client perspective, DirectAccess is an IPv6 only solution. All communication between the DirectAccess client and server takes place exclusively over IPv6. This can make things challenging for network engineers tasked with administering network devices using SSH over a DirectAccess connection. Often network devices don’t have corresponding hostname entries in DNS, and attempting to connect directly to an IPv4 address over a DirectAccess connection will fail.

To resolve this issue, it is necessary to create internal DNS records that resolve to IPv4 addresses for each network device. With that, the DNS64 service on the DirectAccess server will create an IPv6 address for the DirectAccess client to use. The NAT64 service will then translate this IPv6 address to IPv4 and connectivity will be established.

However, for many large organizations this might not be feasible. You may have hundreds or thousands of devices on your network to administer, and creating records in DNS for all these devices will take some time. As a temporary workaround, it is possible to determine the NAT64 IPv6 address for any network device and use that for remote network administration.

The process is simple. On a client that is connected remotely via DirectAccess, resolve the name of a known internal server to an IP address. The quickest and easiest way to do that is simply to ping an internal server by its hostname and note the IPv6 address it resolves to.

SSH Administration over a DirectAccess Connection

Now copy the first 96 bits of that address (everything up to and including the 7777::) and then append the IPv4 address of the network device you wish to manage in familiar dotted-decimal notation. The IPv6 address you create should look something like this:

fd74:45f9:4fae:7777::172.16.1.254

Enter this IPv6 address in whichever tool you use to manage your network devices and it should work. Here’s an example using the popular Putty tool connecting via SSH to a network device in my lab.

SSH Administration over a DirectAccess Connection

Figure 1 – DirectAccess Client IPv6 Prefix w/Appended IPv4 Address

SSH Administration over a DirectAccess Connection

Figure 2 – Successful connection over DirectAccess with Putty.

Going forward I would strongly recommend that you make it part of your normal production implementation process and procedures to create DNS records for all network devices. In the future you’ll absolutely have to do this for IPv6, so now is a good time to get in the habit of doing this. It will make your life a lot easier, trust me!

Please note that adding entries to the local HOSTS file of a DirectAccess client does not work! The name must be resolved by the DNS64 service on the DirectAccess server in order to work properly. Although you could populate the local HOSTS file with names and IPv6 addresses using the method I described above, it would cause problems when the client was on the internal network or connected remotely using traditional client-based VPN, so it is best to avoid using the HOSTS file altogether.

DirectAccess DNS Not Working Properly

Name resolution and proper DNS server configuration is vital to the functionality of DirectAccess. When performing initial configuration of DirectAccess, or making changes to the DNS server configuration after initial configuration, you may notice the operations status for DNS indicates Critical, and that the operations state shows Server responsiveness.

DirectAccess DNS Not Working Correctly

Highlighting the DNS server on the Operations Status page and viewing the details shows that DNS is not working properly with the following error message:

None of the enterprise DNS servers <IPv6_address> used by DirectAccess
clients for name resolution are responding. This might affect DirectAccess
client connectivity to corporate resources.

DirectAccess DNS Not Working Correctly

There are a number of things that can contribute to this problem, but a common cause is an error made when assigning a DNS server to a specific DNS suffix. An inexperienced DirectAccess administrator might specify the IPv4 address of an internal corporate DNS server, which is incorrect. The DNS server IPv4 address should be the address assigned to the DirectAccess server’s internal network interface.

The best way to ensure that the DNS server is configured correctly for DirectAccess is to delete the existing entry and then click Detect.

DirectAccess DNS Not Working Correctly

An IPv6 address will be added automatically. This is the IPv6 address of the DNS64 service running on the DirectAccess server, which is how the DNS server should be configured for proper DirectAccess operation.

DirectAccess DNS Not Working Correctly

Once the changes have been saved and applied, the DNS server should once again respond and the status should return to Working.

DirectAccess DNS Not Working Correctly

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