Always On VPN Certificate Requirements for IKEv2

Always On VPN Certificate Requirements for IKEv2Internet Key Exchange version 2 (IKEv2) is one of the VPN protocols supported for Windows 10 Always On VPN deployments. When the VPN server is Windows Server 2016 with the Routing and Remote Access Service (RRAS) role configured, a computer certificate must first be installed on the server to support IKEv2. There are some unique requirements for this certificate, specifically regarding the subject name and Enhanced Key Usage (EKU) configuration. In addition, some deployment scenarios may require a certificate to be provisioned to the client to support IKEv2 VPN connections.

Server Certificate

The IKEv2 certificate on the VPN server must be issued by the organization’s internal private certification authority (CA). It must be installed in the Local Computer/Personal certificate store on the VPN server. The subject name on the certificate must match the public hostname used by VPN clients to connect to the server, not the server’s hostname. For example, if the VPN server’s hostname is VPN1 and the public FQDN is vpn.example.net, the subject field of the certificate must include vpn.example.net, as shown here.

Always On VPN Certificate Requirements for IKEv2

In addition, the certificate must include the Server Authentication EKU (1.3.6.1.5.5.7.3.1). Optionally, but recommended, the certificate should also include the IP security IKE intermediate EKU (1.3.6.1.5.5.8.2.2).

Always On VPN Certificate Requirements for IKEv2

Client Certificate

Client certificate requirements vary depending on the type of VPN tunnel and authentication method being used.

User Tunnel

No certificates are required on the client to support IKEv2 when using MSCHAPv2, EAP-MSCHAPv2, or Protected EAP (PEAP) with MSCHAPv2. However, if the option to verify the server’s identity by validating the certificate is selected when using PEAP, the client must have the certificates for the root CA and any subordinate CAs installed in its Trusted Root Certification and Intermediate Certificate Authorities certificate stores, respectively.

User Tunnel with Certificate Authentication

Using certificate authentication for the user tunnel is the recommended best practice for Always On VPN deployments. A client certificate must be installed in the Current User/Personal store to support PEAP authentication with smart card or certificate authentication. The certificate must include the Client Authentication EKU (1.3.6.1.5.5.7.3.2).

Always On VPN Certificate Requirements for IKEv2

Device Tunnel

A computer certificate must be installed in the Local Computer/Personal certificate store to support IKEv2 machine certificate authentication and the Always On VPN device tunnel. The certificate must include the Client Authentication EKU (1.3.6.1.5.5.7.3.2).

Always On VPN Certificate Requirements for IKEv2

More information about configuring the Always On VPN device tunnel can be found here.

Additional Information

Always On VPN with Trusted Platform Module (TPM) Certificates

Always On VPN Protocol Recommendations for Windows Server 2016 RRAS

Always On VPN and Windows Server RRAS

Always On VPN 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

Always On VPN RasMan Device Tunnel Failure

Always On VPN RasMan Device Tunnel FailureAn Always On VPN device tunnel is an optional configuration for Windows 10 Enterprise edition clients designed to provide machine-level remote network connectivity. This capability provides feature parity with DirectAccess for domain-joined clients to support scenarios such as logging on without cached credentials and unattended remote support, among others.

Device Tunnel Failure

When configuring a Windows 10 client to use an Always On VPN device tunnel, you may find that the device tunnel works without issue after initial deployment but fails to connect after the computer restarts. In addition, the Windows event log will include an Event ID: 1000 application error with the following error message:

Faulting application name: svchost.exe_RasMan

Always On VPN RasMan Device Tunnel Failure

Known Issue

This can occur when a Windows 10 machine is configured with a device tunnel only (no user tunnel). This is a known issue with Windows 10 v1709. It has been resolved in Windows 10 v1803 (RS4).

Additional Information

Windows 10 Always On VPN Device Tunnel Step-by-Step Configuration using Powershell

Deleting an Always On VPN Device Tunnel

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

NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

NetMotion Mobility for DirectAccess Administrators – Split vs. Force TunnelingDirectAccess employs a split tunneling network model by default. In this configuration, only network traffic destined for the internal network (as defined by the administrator) is tunneled over the DirectAccess connection. All other network traffic is routed directly over the Internet.

Force Tunneling Use Cases

For a variety of reasons, administrators may want to configure DirectAccess to use force tunneling, requiring all client traffic be routed over the DirectAccess connection, including public Internet traffic. Commonly this is done to ensure that all traffic is logged and, importantly, screened and filtered to enforce acceptable use policy and to prevent malware infection and potential loss of data.

DirectAccess and Force Tunneling

Enabling force tunneling for DirectAccess is not trivial, as it requires an on-premises proxy server to ensure proper functionality when accessing resources on the public Internet. You can find detailed guidance for configuring DirectAccess to use force tunneling here.

NetMotion Mobility and Force Tunneling

With NetMotion Mobility, force tunneling is enabled by default. So, if split tunneling is desired, it must be explicitly configured. Follow the steps below to create a split tunneling policy.

Create a Rule Set

  1. Open the NetMotion Mobility management console and click Policy > Policy Management.
  2. Click New.
  3. Enter a descriptive name for the new rule set.
  4. Click Ok.

NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

Create a Rule

  1. Click New.
  2. Enter a descriptive name for the new rule.
  3. Click Ok.

NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

Define an Action

  1. Click on the Actions tab.
  2. In the Addresses section check the box next to Allow network traffic for address(es)/port(s).NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling
  3. In the Base section select Pass through all network traffic.NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

Define the Internal Network

  1. In the Policy rule definition section click the address(es)/port(s) link.NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling
  2. Click Add.
  3. In the Remote Address column select Network Address.
  4. Enter the network prefix and prefix length that corresponds to the internal network.
  5. Click Ok.
  6. Repeat the steps above to add any additional internal subnets, as required.
  7. Click Ok.
  8. Click Save.
  9. Click Save.NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

Assign the Policy

  1. Click on the Subscribers tab.
  2. Choose a group to assign the policy to. This can be users, groups, devices, etc.NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling
  3. Click Subscribe.
  4. Select the Split Tunneling policy.
  5. Click Ok.NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

Validation Testing

With split tunneling enabled the NetMotion Mobility client will be able to securely access internal network resources over the Mobility connection, but all other traffic will be routed over the public Internet. To confirm this, first very that internal resources are reachable. Next, open your favor Internet search engine and enter “IP”. The IP address you see should be the IP address of the client, not the on-premises gateway.

Summary

I’ve never been a big fan of force tunneling with DirectAccess. Not only is it difficult to implement (and requires additional infrastructure!) the user experience is generally poor. There are usability issues especially with captive portals for Wi-Fi, and performance often suffers. In addition, enabling force tunneling precludes the use of strong user authentication with one-time passwords.

With NetMotion Mobility, force tunneling is on by default, so no configuration changes are required. The user experience is improved as NetMotion Mobility intelligently recognizes captive portals. Performance is much better too. In addition, NetMotion Mobility is more flexible, allowing for the use of OTP authentication with force tunneling. Also, with NetMotion Mobility force tunneling is not a global setting. You can selectively apply force tunneling to users and/or groups as necessary.

Additional Information

NetMotion Mobility as an Alternative for Microsoft DirectAccess

NetMotion Mobility for DirectAccess Administrators – Trusted Network Detection

Enabling Secure Remote Administration for the NetMotion Mobility Console

NetMotion Mobility Device Tunnel Configuration

 

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