The Workplace Ninja Summit takes place from 12-14 September 2022 in Lucerne, Switzerland. The conference focuses on endpoint management and security with platforms such as System Center Configuration Manager (SCCM) and Microsoft Endpoint Manager/Intune.
Conference Sessions
If you are participating in the conference, be sure to attend one of my sessions! I’m delivering the following three talks during the event.
This session will explore the options for deploying enterprise PKI certificates using Intune. I’ll be sharing lots of security and implementation best practices.
This talk will dive into the options for deploying Always On VPN using Intune. I’ll be covering many tips, tricks, and best practices and shining a light on many limitations and shortcomings of using Intune for Always On VPN.
Join Me!
Unfortunately, the conference is sold out, so if you haven’t made arrangements to attend you’ll have to wait until next year. If you are attending, please be sure to say hello!
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.
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.”
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 notwork 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 viableoption. 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.
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 onlysupported 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.
A Windows 7 or Windows 8.x/10 client may fail to establish a DirectAccess connection using the IP-HTTPS IPv6transition technology. When troubleshooting this issue, running ipconfig.exe show that the media state for the tunnel adapter iphttpsinterface is Media disconnected.
Running the Get-NetIPHttpsState PowerShell command on Windows 8.x/10 clients or the netsh interface httpstunnel show interface command on Windows 7 clients returns an error code of 0x800b0109 with an interface status Failed to connect to the IPHTTPS server; waiting to reconnect.
Error code 0x800b0109 translates to CERT_E_UNTRUSTEDROOT, indicating the client was unable to establish an IP-HTTPS connection because the certificate presented during the SSL handshake was issued by a certification authority that was not trusted. This commonly occurs when the DirectAccess server is configured with an SSL certificate issued by the internal PKI and DirectAccess clients are provisioned using offline domain joinwithout using the /rootcacerts switch. This can also happen if DirectAccess is configured to use a self-signed certificate for IP-HTTPS, and the certificate is either renewed or DirectAccess is uninstalled and reinstalled.
To resolve IP-HTTPS error code 0x800b0109, obtain the root certificate for the certificate authority that issued the SSL certificate used for IP-HTTPS and import it in to the DirectAccess client’s Trusted Root Certification Authorities local computer certificate store. Once complete, restart the IP helper service to reinitiate an IP-HTTPS connection.
