Always On VPN Load Balancing with Loadbalancer.org

Recently, I had the opportunity to deploy the Loadbalancer.org load balancer as part of an enterprise Always On VPN deployment. In the past, I’ve published guidance for using F5 BIG-IP, Citrix ADC (formerly NetScaler), and Kemp LoadMaster, so in this post, I’ll provide guidance for configuring Loadbalancer.org for Always On VPN.

IKEv2

Open the Loadbalancer.org management console and follow the steps below to configure Always On VPN load balancing on the appliance.

Create Virtual Service

Create a layer 4 virtual service for IKEv2.

  1. Click Cluster Configuration.
  2. Click Layer 4 – Virtual Services.
  3. Click Add a new Virtual Service.
  4. Enter a descriptive name for the virtual service in the Label field.
  5. Enter the virtual IP address (VIP) for the service in the IP Address field.
  6. Enter 500,4500 in the Ports field.
  7. Select UDP from the Protocol drop-down list.
  8. Select NAT from the Forwarding Method drop-down list.
  9. Click Update.

Add Real Servers

Add real servers to the virtual service.

  1. Click Layer 4 – Real Servers.
  2. Click Add a new Real Server next to the IKEv2 virtual service.
  3. Enter a descriptive name for the real server in the Label field.
  4. Enter the IP address of the real server in the Real Server IP Address field.
  5. Click Update.
  6. Repeat these steps for each additional VPN server in the cluster.

SSTP

Follow the steps below to configure SSTP load balancing on the appliance.

Create Virtual Service

Create a layer 4 virtual service for SSTP.

  1. Click Cluster Configuration.
  2. Click Layer 4 – Virtual Services.
  3. Click Add a new Virtual Service.
  4. Enter a descriptive name for the virtual service in the Label field.
  5. Enter the virtual IP address (VIP) for the service in the IP Address field.
  6. Enter 443 in the Ports field.
  7. Select TCP from the Protocol drop-down list.
  8. Select NAT from the Forwarding Method drop-down list.
  9. Click Update.

Configure Virtual Service Health Check

Update the health check method for the SSTP virtual service.

  1. Click Layer 4 – Virtual Services.
  2. Click Modify on the SSTP virtual service.
  3. Select Negotiate from the Check Type drop-down list in the Health Checks section.
  4. Enter 443 in the Check Port field.
  5. Select HTTPS from the Protocol drop-down list.
  6. Enter /sra_{BA195980-CD49-458b-9E23-C84EE0ADCD75}/ in the Request to send field.
  7. Enter 401 in the Response expected field.
  8. Click Update.

Note: Using the Negotiate health check type for the SSTP monitor on Loadbalancer.org appliances requires version 8.13.0 or later. Administrators can use the External script option when using earlier releases of Loadbalancer.org appliances. An SSTP health check script for Loadbalancer.org can be found here.

Add Real Servers

Add real servers to the virtual service.

  1. Click Layer 4 – Real Servers.
  2. Click Add a new Real Server next to the SSTP virtual service.
  3. Enter a descriptive name for the real server in the Label field.
  4. Enter the IP address of the real server in the Real Server IP Address field.
  5. Click Update.
  6. Repeat these steps for each additional VPN server in the cluster.

Review

Once complete, click System Overview to view the overall health of your VPN servers.

Summary

The Loadbalancer.org appliance is an efficient, cost-effective, and easy-to-configure load-balancing solution that works well with Always On VPN implementations. It’s available as a physical or virtual appliance. There’s also a cloud-based version. It also includes advanced features such as TLS offload, web application firewall (WAF), global server load balancing (GSLB), and more. If you are looking for a layer 4-7 load balancer for Always On VPN and other workloads, be sure to check them out.

Additional Information

Loadbalancer.org Virtual Appliance

SSTP Health Check Script for Loadbalancer.org

Always On VPN Discord Channel

I’m excited to announce the launch of a brand-new Discord channel dedicated to administrators working with Always On VPN! Whether you’re a seasoned pro or just getting started, this community is designed to be your go-to hub for collaboration, troubleshooting, and staying up to date on all things Always On VPN. The channel was established by my good friend Leo D’Arcy, the creator of the popular Always On VPN Dynamic Profile Generator (DPC) software.

Why Discord?

Always On VPN is a powerful solution for secure, seamless remote connectivity, but managing it comes with its own set of challenges. From configuration quirks to deployment strategies, administrators often need a space to share insights, ask questions, and learn from one another in real-time. That’s where our new Discord channel comes in.

Community Forum

Discord offers a dynamic, user-friendly platform for instant communication and community building. Unlike forums or email threads, it’s a place where you can start a conversation, jump into live discussions, share resources, ask questions, share important insights or experiences, and much more.

Channels

Today, the Always On VPN Discord channel is part of the Microsoft Remote Access User Group Discord Server. It consists of multiple channels divided into the following topics.

General – This is a great place to introduce yourself and say hello to everyone!

DPC-Development – Here, you can ask questions about DPC, provide feedback, and suggest new features and functionality.

DPC-Chat – This channel is for administrators to discuss all things DPC, including deployment strategies, operation, support, and more.

Aovpn-Chat – If you’ve deployed Always On VPN but aren’t using DPC, this is your channel! Although DPC is fantastic, not everyone is using it. In this channel, you can submit questions and share general information about Always On VPN.

Gsa-Chat – We’ve also included a Microsoft Entra Global Secure Access channel for the new Microsoft Security Service Edge (SSE) solution, which includes Entra Private Access. This channel is pretty quiet right now. Hopefully, it will grow in the future!

DirectAccess-Chat – Yes, we realize some of you are still running DirectAccess, so there’s also a channel for you! Feel free to drop in and ask questions here, hopefully about migrating soon. 😉

Who Is This For?

This channel is open to anyone managing Microsoft secure remote access products. Whether you’re an IT administrator in a small business, an enterprise network engineer, or a consultant helping clients stay connected. If you’re working with Microsoft remote access technologies, this is the place to be!

Why Not Reddit?

Funny story: I tried to create an Always On VPN subreddit a few years ago. It lasted one day before it was banned! No reason was given, and I couldn’t get anyone from Reddit to respond. I answer questions ad hoc on Reddit all the time, but there’s no dedicated space for Always On VPN or Microsoft remote access in general.

How To Join

Joining our Discord channel is easy.

  1. Click this link.
  2. Set up your Discord account if you don’t already have one. It’s free and only takes a minute!
  3. Optionally, you can download the Discord app here.
  4. Say hello and introduce yourself in the #general channel.
  5. Explore the other channels, ask questions, give feedback, and share your expertise!

See You There!

Leo and I are on the forums daily, as are many other experienced Always On VPN administrators. We encourage you to share your expertise, ask questions, and help others along the way. The more we contribute, the stronger this resource becomes for everyone. Join us today!

Additional Information

Always On VPN Dynamic Profile Configurator (DPC)

DPC on GitHub

Managed Certificates for Remote Desktop Protocol

The Remote Desktop Protocol (RDP) is arguably the most widely used protocol for Windows remote server administration. RDP uses Transport Layer Security (TLS) for server authentication, data encryption, and integrity. However, the default configuration of TLS for RDP in Windows is less than ideal.

RDP Self-Signed Certificate

By default, RDP uses a self-signed certificate for TLS operations. TLS with self-signed certificates is a bad security practice because they are not validated by a trusted certificate authority (CA), making it impossible for clients to verify the authenticity of the server they are connecting to, which can lead to interception attacks.

Certificate Warning

Most administrators have encountered a warning error when connecting to a remote host via RDP using a self-signed RDP certificate.

“The remote computer could not be authenticated due to problems with its security certificate. It may be unsafe to proceed.”

Nmap

You can view the default self-signed certificate with the Nmap utility by running the following command.

nmap.exe -n -p 3389 <hostname> –script ssl-cert

Managed Certificates

A better solution for RDP TLS is to use managed certificates issued by an enterprise Public Key Infrastructure (PKI) such as Microsoft Active Directory Certificate Services (AD CS). AD CS is widely deployed in AD domain environments and can be configured to issue certificates for RDP TLS.

AD CS

To configure AD CS to issue RDP certificates, perform the following steps.

Certificate Template

On an issuing CA or an administrative workstation with the Remote Server Administration Tools (RSAT) installed, open the Certificate Templates management console (certtmpl.msc) and perform the following steps.

*My apologies for the list numbering format issues below. Microsoft Word and WordPress can’t seem to agree on the list format. Hopefully, you can figure it out, though. 🙂

  1. Right-click the Workstation Authentication template and choose Duplicate Template.
  2. Select the Compatibility tab.
    1. Select the operating system (OS) version corresponding to the oldest OS hosting the issuing CA role in your environment from the Certification Authority drop-down list.
    1. Select the OS version corresponding to your environment’s oldest supported server or client OS from the Certificate recipient drop-down list.
  3. Select the General tab.
    1. Enter a descriptive name in the Template display name field.
    1. Select an appropriate validity period for your environment. The best practice is to limit the validity period to one year or less.
  4. Select the Cryptography tab.
    1. From the Provider Category drop-down list, choose Key Storage Provider.
    1. From the Algorithm name drop-down list, choose RSA.
    1. In the Minimum key size field, enter 2048.
    1. From the Request hash drop-down list, choose SHA256.
  5. Select the Subject Name tab.
    1. From the Subject name format drop-down list, select DNS name.
    1. Ensure that DNS name is also checked in the subject alternate name section.
  6. Select the Extensions tab.
    1. Click on Application Policies.
    1. Click Edit.
    1. Select Client Authentication.
    1. Click Remove.
    1. Click Add.
    1. Click New.
    1. Enter Remote Desktop Authentication in the Name field.
    1. Enter 1.3.6.1.4.1.311.54.1.2 in the Object identifier field.
    1. Click Ok.
    1. Select Remote Desktop Authentication.
    1. Click Ok.
  7. Select the Security tab.
    1. Click Domain Computers.
    1. Grant the Read and Enroll permissions.
  8. Click Ok.

Next, open the Certification Authority management console (certsrv.msc) and follow the steps below to publish the certificate.

  1. Expand the CA.
  2. Right-click Certificate Templates and choose New > Certificate Template to Issue.
  3. Select the Remote Desktop Authentication certificate template.
  4. Click Ok.

Group Policy

Next, on a domain controller or a workstation with the RSAT tools installed, open the Group Policy Management console (gmpc.msc) and perform the following steps to create a new GPO to enroll domain computers for the Remote Desktop Authentication certificate

  1. Right-click Group Policy Objects and choose New.
  2. Enter a descriptive name for the GPO in the Name field.
  3. Click Ok.
  4. Right-click the GPO and choose Edit.
  5. Navigate to Computer Configuration > Policies > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Security.
  6. Double-click Server authentication certificate template.
  7. Select Enabled.
  8. Enter the name of the Remote Desktop Authentication certificate template in the Certificate Template Name field. Note: Be sure to enter the template name, not the template display name!
  9. Click Ok.

Once complete, link the GPO to the domain or OU to target the servers and workstations to which you wish to deploy the RDP certificate.

Validate Certificate

After updating group policy on a target resource, you’ll find that Nmap now shows the enterprise PKI-issued certificate used for RDP connections.

Additional Information

Understanding the Remote Desktop Protocol (RDP)