All posts tagged routing and remote access service

Always On VPN IPsec Root Certificate Configuration Issue

Always On VPN Device Tunnel Status Indicator When configuring a Windows Routing and Remote Access Service (RRAS) server to support Internet Key Exchange version 2 (IKEv2) VPN connections, it is essential for the administrator to define the root certification authority for which to accept IPsec security associations (SAs). Without defining this setting, the VPN server will accept a device certificate issued by any root certification authority defined in the Trusted Root Certification Authorities store. Details about configuring IKEv2 security and defining the root certification authority can be found here.

Multiple Root Certificates

Administrators may find that when they try to define a specific root certification authority, the setting may not be implemented as expected. This commonly occurs when there is more than one root certificate in the Trusted Root Certification Authorities store for the same PKI.

Certificate Selection

When running the PowerShell command Set-VpnAuthProtocol to define the root certification authority, PowerShell may ignore the administrator-defined certificate and choose a different one, as shown here. This will result in failed IPsec VPN connections from Windows 10 Always On VPN clients using IKEv2.

Certificate Publishing

This issue can occur when root certification authority certificates are published using Active Directory group policy. It appears that Windows prefers Active Directory group policy published certificates over those published directly in the Certification Authorities Container in Active Directory. To resolve this issue, remove any group policy objects that are publishing root certification authority certificates and ensure those root certificates are published in the Certification Authorities container in Active Directory.

PowerShell Script

A PowerShell script to configure this setting that can be found in my Always On VPN GitHub repository here. I have updated this script to validate the defined root certification authority certificate and warn the user if it does not match.

Additional Information

Set-Ikev2VpnRootCertificate.ps1 PowerShell script on GitHub

Windows 10 Always On VPN IKEv2 Security Configuration

Windows 10 Always On VPN IKEv2 Load Balancing and NAT

Windows 10 Always On VPN IKEv2 Features and Limitations

Windows 10 Always On VPN IKEv2 Fragmentation

Windows 10 Always On VPN IKEv2 Certificate Requirements

Always On VPN SSTP Certificate Binding Error

Always On VPN SSTP Certificate Binding Error When configuring a Windows Server with the Routing and Remote Access Service (RRAS) role to support Windows 10 Always On VPN connections, the administrator may encounter the following error message when installing or updating the TLS certificate used for Secure Socket Tunneling Protocol (SSTP) connections.

“The thumbprint (cert hash) of the certificate used for Secure Socket Tunneling Protocol (SSTP) is different than the certificate bound to the Web listener (HTTP.sys). Configure SSTP to use the default certificate or the certificate bound to SSL. You can configure web server applications to use the same certificate used by SSTP.”

Always On VPN SSTP Certificate Binding Error

IIS Binding

Most commonly this error can occur if an administrator mistakenly binds a TLS certificate directly in IIS. To resolve this problem, open the IIS management console (inetmgr.exe), navigate to the Default Web Site and click Bindings in the Actions section. Highlight the HTTPS binding and click Remove. Once complete, open an elevated command window and run the iisreset.exe command.

Always On VPN SSTP Certificate Binding Error

Netsh

In some instances, the administrator may find no certificate bindings in the IIS management console. However, a certificate binding may still be present. To confirm, open an elevated command window and run the following command.

netsh.exe http show sslcert

Always On VPN SSTP Certificate Binding Error

Remove existing certificate binding by running the following commands.

netsh.exe http delete sslcert ipport=0.0.0.0:443
netsh.exe http delete sslcert ipport=[::]:443

SSTP Configuration

When configuring SSTP in RRAS for Always On VPN, certificate assignment should always be performed using the Routing and Remote Access management console (rrasmgmt.msc). No changes are required to be made in the IIS management console for SSTP.

Additional Information

Windows 10 Always On VPN SSL Certificate Requirements for SSTP

Windows 10 Always On VPN SSTP Load Balancing with Citrix NetScaler ADC Load Balancer

Windows 10 Always On VPN SSTP Load Balancing with Kemp LoadMaster Load Balancer

Windows 10 Always On VPN SSTP Load Balancing with F5 BIG-IP Load Balancer

7 Comments

by Richard M. Hicks on August 31, 2020 • Permalink

Posted by Richard M. Hicks on August 31, 2020

https://directaccess.richardhicks.com/2020/08/31/always-on-vpn-sstp-certificate-binding-error/

Always On VPN IKEv2 Load Balancing and NAT

Always On VPN IKEv2 Load Balancing and NAT Over the last few weeks, I’ve worked with numerous organizations and individuals troubleshooting connectivity and performance issues associated with Windows 10 Always On VPN, and specifically connections using the Internet Key Exchange version 2 (IKEv2) VPN protocol. An issue that appears with some regularity is when Windows 10 clients fail to connect with error 809. In this scenario, the server will accept connections without issue for a period of time and then suddenly stop accepting requests. When this happens, existing connections continue to work without issue in most cases. Frequently this occurs with Windows Server Routing and Remote Access Service (RRAS) servers configured in a clustered array behind an External Load Balancer (ELB).

Network Address Translation

It is not uncommon to use Network Address Translation (NAT) when configuring Always On VPN. In fact, for most deployments the public IP address for the VPN server resides not on the VPN server, but on an edge firewall or load balancer connected directly to the Internet. The firewall/load balancer is then configured to translate the destination address to the private IP address assigned to the VPN server in the perimeter/DMZ or the internal network. This is known a Destination NAT (DNAT). Using this configuration, the client’s original source IP address is left intact. This configuration presents no issues for Always On VPN.

Source Address Translation

When troubleshooting these issues, the common denominator seems to be the use of Full NAT, which includes translating the source address in addition to the destination. This results in VPN client requests arriving at the VPN server as appearing not to come from the client’s original IP address, but the IP address of the network device (firewall or load balancer) that is translating the request. Full NAT may be explicitly configured by an administrator, or in the case of many load balancers, configured implicitly because the load balancer is effectively proxying the connection.

Known Issues

IKEv2 VPN connections use IPsec for encryption, and by default, Windows limits the number of IPsec Security Associations (SAs) coming from a single IP address. When a NAT device is performing destination/full NAT, the VPN server sees all inbound IKEv2 VPN requests as coming from the same IP address. When this happens, clients connecting using IKEv2 may fail to connect, most commonly when the server is under moderate to heavy load.

Resolution

The way to resolve this issue is to ensure that any load balancers or NAT devices are not translating the source address but are performing destination NAT only. The following is configuration guidance for F5, Citrix ADC (formerly NetScaler), and Kemp load balancers.

F5

On the F5 BIG-IP load balancer, navigate to the Properties > Configuration page of the IKEv2 UDP 500 virtual server and choose None from the Source Address Translation drop-down list. Repeat this step for the IKEv2 UDP 4500 virtual server.

Always On VPN IKEv2 Load Balancing and NAT

Citrix ADC

On the Citrix ADC load balancer, navigate to System > Settings > Configure Modes and check the option to Use Subnet IP.

Always On VPN IKEv2 Load Balancing and NAT

Next, navigate to Traffic Management > Load Balancing > Service Groups and select the IKEv2 UDP 500 service group. In the Settings section click edit and select Use Client IP. Repeat these steps for the IKEv2 UDP 4500 service group.

Always On VPN IKEv2 Load Balancing and NAT

Kemp

On the Kemp LoadMaster load balancer, navigate to Virtual Services > View/Modify Services and click Modify on the IKEv2 UDP 500 virtual service. Expand Standard Options and select Transparency. Repeat this step for the IKEv2 UDP 4500 virtual service.

Always On VPN IKEv2 Load Balancing and NAT

Caveat

Making the changes above may introduce routing issues in your environment. When configuring these settings, it may be necessary to configure the VPN server’s default gateway to use the load balancer to ensure proper routing. If this is not possible, consider implementing the workaround below.

Workaround

To fully resolve this issue the above changes should be made to ensure the VPN server can see the client’s original source IP address. If that’s not possible for any reason, the following registry key can be configured to increase the number of established SAs from a single IP address. Be advised this is only a partial workaround and may not fully eliminate failed IKEv2 connections. There are other settings in Windows that can prevent multiple connections from a single IP address which are not adjustable at this time.

To implement this registry change, open an elevated PowerShell command window on the RRAS server and run the following commands. Repeat these commands on all RRAS servers in the organization.

New-ItemProperty -Path ‘HKLM:SYSTEM\CurrentControlSet\Services\IKEEXT\Parameters\’ -Name IkeNumEstablishedForInitialQuery -PropertyType DWORD -Value 50000 -Force

Restart-Service IKEEXT -Force -PassThru

Additional Information

IPsec Traffic May Be Blocked When A Computer is Behind a Load Balancer

Windows 10 Always On VPN IKEv2 Load Balancing with Citrix NetScaler ADC

Windows 10 Always On VPN IKEv2 Load Balancing with F5 BIG-IP

Windows 10 Always On VPN IKEv2 Load Balancing with Kemp LoadMaster

60 Comments

by Richard M. Hicks on April 13, 2020 • Permalink

Posted by Richard M. Hicks on April 13, 2020

https://directaccess.richardhicks.com/2020/04/13/always-on-vpn-ikev2-load-balancing-and-nat/

Remote Access Questions and Answers Webinar Hosted by Kemp

Join me this Thursday, April 9 at 10:00AM EDT for a Remote Access Q&A session hosted by Kemp Technologies. During this free live webinar, I’ll be answering all your questions as they relate to enterprise mobility, remote access, scalability and performance, security, and much more. Topics are not limited to Kemp products at all, so feel free to join and ask me anything you like! Register now and submit your questions!

Remote Access Q&A Webinar Hosted by Kemp

Always On VPN Device Tunnel Only Deployment Considerations

Always On VPN Device Tunnel Only Deployment Considerations Recently I wrote about Windows 10 Always On VPN device tunnel operation and best practices, explaining its common uses cases and requirements, as well as sharing some detailed information about authentication, deployment recommendations, and best practices. I’m commonly asked if deploying Always On VPN using the device tunnel exclusively, as opposed to using it to supplement the user tunnel, is supported or recommended. I’ll address those topics in detail here.

Device Tunnel Only?

To start, yes, it is possible to deploy Windows 10 Always On VPN using only the device tunnel. In this scenario the administrator will configure full access to the network instead of limited access to domain infrastructure services and management servers.

Is It Recommended?

Generally, no. Remember, the device tunnel was designed with a specific purpose in mind, that being to provide pre-logon network connectivity to support scenarios such as logging on without cached credentials. Typically, the device tunnel is best used for its intended purpose, which is providing supplemental functionality to the user tunnel.

Deployment Considerations

The choice to implement Always On VPN using only the device tunnel is an interesting one. There are some potential advantages to this deployment model, but it is not without some serious limitations. Below I’ve listed some of the advantages and disadvantages to deploying the device tunnel alone for Windows 10 Always On VPN.

Advantages

Using the device tunnel alone does have some compelling advantages over the standard two tunnel (device tunnel/user tunnel) deployment model. Consider the following.

Single VPN Connection – Deploying the device tunnel alone means a single VPN connection to configure, deploy, and manage on the client. This also results in less concurrent connections and, importantly, less IP addresses to allocate and provision.
Reduced Infrastructure – The device tunnel is authenticated using only the device certificate. This certificate check is performed directly on the Windows Server Routing and Remote Access Service (RRAS) VPN server, eliminating the requirement to deploy Network Policy Server (NPS) servers for authentication.
User Transparency – The device tunnel does not appear in the modern Windows UI. The user will not see this connection if they click on the network icon in the notification area. In addition, they will not see the device tunnel connection in the settings app under Network & Internet > VPN. This prevents casual users from playing with the connection settings, and potentially deleting the connection entirely. It’s not that they can’t delete the device tunnel however, it’s just not as obvious.
Simplified Deployment – Deploying the device tunnel is less complicated than deploying the user tunnel. The device tunnel is provisioned once to the device and available to all users. This eliminates the complexity of having to deploy the user tunnel in each individual user’s profile.

Disadvantages

While there are some advantages to using the device tunnel by itself, this configuration is not without some serious limitations. Consider the following.

IKEv2 Only – The device tunnel uses the IKEv2 VPN protocol exclusively. It does not support SSTP. While IKEv2 is an excellent protocol in terms of security, it is commonly blocked by firewalls. This will prevent some users from accessing the network remotely depending on their location.
Limited OS Support – The device tunnel is only supported on Windows 10 Enterprise edition clients, and those clients must be joined to a domain. Arguably the device tunnel wouldn’t be necessary if the client isn’t domain joined, but some organizations have widely deployed Windows 10 Professional, which would then preclude them from being able to use the device tunnel.
Machine Certificate Authentication Only – The device tunnel is authenticated using only the certificate issued to the device. This means anyone who logs on to the device will have full access to the internal network. This may or may not be desirable, depending on individual requirements.
No Mutual Authentication – When the device tunnel is authenticated, the server performs authentication of the client, but the client does not authenticate the server. The lack of mutual authentication increases the risk of a man-in-the-middle attack.
CRL Checks Not Enforced – By default, RRAS does not perform certificate revocation checking for device tunnel connections. This means simply revoking a certificate won’t prevent the device from connecting. You’ll have to import the client’s device certificate into the Untrusted Certificates certificate store on each VPN server. Fortunately, there is a fix available to address this limitation, but it involves some additional configuration. See Always On VPN Device Tunnel and Certificate Revocation for more details.
No Support for Azure Conditional Access – Azure Conditional Access requires EAP authentication. However, the device tunnel does not use EAP but instead uses a simple device certificate check to authenticate the device.
No Support for Multifactor Authentication – As the device tunnel is authenticated by the RRAS VPN server directly and authentication requests are not sent to the NPS server, it is not possible to integrate MFA with the device tunnel.
Limited Connection Visibility – Since the device tunnel is designed for the device and not the user it does not appear in the list of active network connections in the Windows UI. There is no user-friendly connection status indicator, although the connection can be viewed using the classic network control panel applet (ncpa.cpl).

Summary

The choice to deploy Windows 10 Always On VPN using the device tunnel alone, or in conjunction with the user tunnel, is a design choice that administrators must make based on their individual requirements. Using the device tunnel alone is supported and works but has some serious drawbacks and limitations. The best experience will be found using the device tunnel as it was intended, as an optional component to provide pre-logon connectivity for an existing Always On VPN user tunnel.

Additional Information

Windows 10 Always On VPN Device Tunnel with Azure VPN Gateway

Windows 10 Always On VPN Device Tunnel and Certificate Revocation

Windows 10 Always On VPN Device Tunnel Configuration with Microsoft Intune

Windows 10 Always On VPN Device Tunnel Does Not Connect Automatically

Windows 10 Always On VPN Device Tunnel Missing in Windows 10 UI

Deleting a Windows 10 Always On VPN Device Tunnel

Windows 10 Always On VPN Device Tunnel Configuration using PowerShell

Windows 10 Always On VPN IKEv2 Features and Limitations

45 Comments

by Richard M. Hicks on April 6, 2020 • Permalink

Posted by Richard M. Hicks on April 6, 2020

https://directaccess.richardhicks.com/2020/04/06/always-on-vpn-device-tunnel-only-deployment-considerations/

Always On VPN SSTP Load Balancing with Citrix NetScaler ADC

Always On VPN SSTP Load Balancing with Citrix NetScaler ADC One of the many advantages of using Windows Server Routing and Remote Access Service (RRAS) as the VPN server to support Windows 10 Always On VPN connections is that it includes support for the Secure Socket Tunneling Protocol (SSTP). SSTP is a TLS-based VPN protocol that is easy to configure and deploy and is very firewall friendly. This ensures consistent and reliable connectivity even behind restrictive firewalls. The Citrix ADC (formerly NetScaler) is a popular platform for load balancing Always On VPN connections. In this article I’ll describe how to configure load balancing on the Citrix ADC for RRAS VPN connections using the SSTP VPN protocol.

Special Note: In December 2019 a serious security vulnerability was discovered on the Citrix ADC that gives an unauthenticated attacker the ability to arbitrarily execute code on the appliance. As of this writing a fix is not available (due end of January 2020) but a temporary workaround can be found here.

Load Balancing SSTP

Previously I’ve written about some of the use cases and benefits of SSTP load balancing as well as the options for offloading TLS for SSTP VPN connections. Load balancing SSTP eliminates single points of failure and enables support for multiple RRAS VPN servers to increase scalability. It is generally recommended that the Citrix ADC be configured to pass through encrypted SSTP VPN connections. However, TLS offloading can be configured to improve performance and reduce resource utilization on VPN servers, if required.

Configuration

Load balancing SSTP on the Citrix ADC is straightforward and not unlike load balancing a common HTTPS web server. Below are specific settings and parameters required to load balance SSTP using the Citrix ADC.

Note: This article is not a comprehensive configuration guide for the Citrix ADC. It assumes the administrator is familiar with basic load balancing concepts and has experience configuring the Citrix ADC.

Service Settings

The load balancing service for SSTP VPN should be configured to use TCP port 443 and the SSL_BRIDGE protocol. If TLS offload is required, TCP port 80 and the HTTP protocol can be configured. Additional configuration is required on the RRAS server when TLS offload is enabled, however. Detailed information for configuring RRAS and SSTP for TLS offload can be found here.

Always On VPN SSTP Load Balancing with Citrix NetScaler ADC

Virtual Server Settings

The virtual server is configured to use TCP port 443. It is recommended to use SSLSESSION persistence.

Always On VPN SSTP Load Balancing with Citrix NetScaler ADC

The LEASTCONNECTION load balancing method is the recommend option for load balancing method.

Always On VPN SSTP Load Balancing with Citrix NetScaler ADC

Service Monitoring

Using the default TCP monitor (tcp-default) is not recommended for monitoring SSTP, as a simple TCP port check does not accurately reflect the health of the SSTP service running on the RRAS server. To more precisely monitor the SSTP service status, a new custom monitor must be created and bound to the load balancing services. Follow the steps below to configure a custom SSTP VPN monitor on the Citrix ADC.

Open the Citrix ADC management console and expand Traffic Management.
Select Monitors.
Click Add.
Enter a descriptive name in the Name field.
Select HTTP form the Type drop-down list and click Select.
Adjust the Interval and Response Time-out values according to your requirements.
Enter 401 in the Response Codes field and click the “+” button.
In the Response Codes field click the “x” next to 200.
In the HTTP Request field enter HEAD /sra_{BA195980-CD49-458b-9E23-C84EE0ADCD75}/.
Check the box next to Secure (not required if TLS offload is enabled).
Select ns_default_ssl_profile_backend from the SSL profile drop-down list (not required if TLS offload is enabled).
Click Create.

Always On VPN SSTP Load Balancing with Citrix NetScaler ADC

Once complete, bind the new service monitor to the load balancing services or service groups accordingly.

TLS Offload

It is generally recommended that TLS offload not be enabled for SSTP VPN. However, if TLS offload is desired, it is configured in much the same way as a common HTTPS web server. Specific guidance for enabling TLS offload on the Citrix ADC can be found here. Details for configuring RRAS and SSTP to support TLS offload can be found here.

Certificates

When enabling TLS offload for SSTP VPN connections it is recommended that the public SSL certificate be installed on the RRAS server, even though TLS processing will be handled on the Citrix ADC and HTTP will be used between the Citrix ADC and the RRAS server. If installing the public SSL certificate on the RRAS server is not an option, additional configuration will be required. Specifically, TLS offload for SSTP must be configured using the Enable-SSTPOffload.ps1 PowerShell script, which can be found here.

Once the script has been downloaded, open an elevated PowerShell command window and enter the following command.

.\Enable-SSTPOffload.ps1 -CertificateHash [SHA256 Certificate Hash of Public SSL Certificate] -Restart

Example:

.\Enable-SSTPOffload.ps1 -CertificateHash ‘C3AB8FF13720E8AD9047DD39466B3C8974E592C2FA383D4A3960714CAEF0C4F2’ -Restart

Re-Encryption

When offloading TLS for SSTP VPN connections, all traffic between the Citrix ADC and the RRAS server will be sent in the clear using HTTP. In some instances, TLS offload is required only for traffic inspection, not performance gain. In this scenario the Citrix ADC will be configured to terminate and then re-encrypt connections to the RRAS server. When terminating TLS on the Citrix ADC and re-encrypting connections to the RRAS server is required, the same certificate must be used on both the Citrix ADC and the RRAS server. Using different certificates on the RRAS server and the load balancer is not supported.

Additional Information

Windows 10 Always On VPN Load Balancing and SSL Offload

SSL Offload Configuration for Citrix ADC (NetScaler)

Windows 10 Always On VPN SSTP Load Balancing with Kemp LoadMaster

Windows 10 Always On VPN SSTP Load Balancing with F5 BIG-IP

Windows 10 Always On VPN Connects then Disconnects

Windows 10 Always On VPN SSL Certificate Requirements for SSTP

4 Comments

by Richard M. Hicks on January 13, 2020 • Permalink

Posted by Richard M. Hicks on January 13, 2020

https://directaccess.richardhicks.com/2020/01/13/always-on-vpn-sstp-load-balancing-with-citrix-netscaler-adc/

Always On VPN Error Code 858

Always On VPN Error Code 858 When configuring Windows 10 Always On VPN using Extensible Authentication Protocol (EAP), the administrator may encounter a scenario in which the client connection fails. The event log will include an event ID 20227 from the RasClient source that includes the following error message.

“The user [domain\username] dialed a connection named [connection name] which has failed. The error code returned on failure is 858.”

Always On VPN Error Code 858

RasClient Error 858

RasClient error code 858 translates to ERROR_EAP_SERVER_CERT_EXPIRED. Intuitively, this indicates that the Server Authentication certificate installed on the Network Policy Server (NPS) has expired. To resolve this issue, renew the certificate on the NPS server.

Additional Information

Windows 10 Always On VPN Network Policy Server (NPS) Load Balancing

Windows 10 Always On VPN and Windows Server 2019 NPS Bug

Windows 10 Always On VPN Error Code 864

Always On VPN IKEv2 Load Balancing Issue with Kemp LoadMaster

Always On VPN IKEv2 Load Balancing Issue with Kemp LoadMaster A recent update to the Kemp LoadMaster load balancer may cause failed connections for Always On VPN connections using IKEv2. SSTP VPN connections are unaffected.

Load Balancing IKEv2

When using the Kemp LoadMaster load balancer to load balance IKEv2, custom configuration is required to ensure proper operation. Specifically, the virtual service must be configured to use “port following” to ensure both the initial request on UDP port 500 and the subsequent request on UDP port 4500 are sent to the same real server. This requires the virtual service to be configured to operate at layer 7. Detailed configuration guidance for load balancing IKEv2 on the Kemp LoadMaster load balancer can be found here.

Always On VPN IKEv2 Load Balancing Issue with Kemp LoadMaster

Issues with LMOS 7.2.48.0

A recent release of the Load Master Operating System (LMOS) v7.2.48.0 introduced a bug that affects UDP services configured to operate at layer 7, which includes IKEv2. This bug breaks Always On VPN connections using IKEv2, resulting in failed connections. When this occurs, the administrator may encounter an error 809 message for device tunnel or user tunnel.

Always On VPN IKEv2 Load Balancing Issue with Kemp LoadMaster

Update Available

Administrators who use the Kemp LoadMaster load balancer to load balance Always On VPN IKEv2 connections and have updated to LMOS 7.2.48.0 are encouraged to update to LMOS 7.2.48.1 immediately. This latest update includes a fix that resolves broken IKEv2 load balancing for Always On VPN. Once the LoadMaster has been updated to 7.2.48.1, Always On VPN connections using IKEv2 should complete successfully.

Additional Information

Windows 10 Always On VPN IKEv2 Load Balancing and NAT

Windows 10 Always On VPN IKEv2 Load Balancing with Kemp LoadMaster Load Balancer

Windows 10 Always On VPN SSTP Load Balancing with Kemp LoadMaster Load Balancer

Windows 10 Always On VPN Load Balancing with Kemp LoadMaster in Azure

Windows 10 Always On VPN Load Balancing Deployment Guide for Kemp Load Balancers

16 Comments

by Richard M. Hicks on November 18, 2019 • Permalink

Posted by Richard M. Hicks on November 18, 2019

https://directaccess.richardhicks.com/2019/11/18/always-on-vpn-ikev2-load-balancing-issue-with-kemp-loadmaster/

Always On VPN Load Balancing with Kemp in Azure

Always On VPN Load Balancing with Kemp in Azure In a recent post I discussed options for load balancing Windows Server Routing and Remote Access Service (RRAS) in Microsoft Azure for Always On VPN. There are many choices available to the administrator, however the best alternative is to use a dedicated Application Delivery Controller (ADC), or load balancer. The Kemp LoadMaster load balancer is an excellent choice here, as it is easy to configure and deploy. It is also very cost effective and offers flexible licensing plans, including a metered licensing option.

Deploy LoadMaster in Azure

To provision a Kemp LoadMaster load balancer in Microsoft Azure, open the Azure management console and perform the following steps.

1. Click Create Resource.
2. Enter LoadMaster in the search field.
3. Click on LoadMaster Load Balancer ADC Content Switch.

Always On VPN Load Balancing with Kemp in Azure

4. Choose an appropriate license model from the Select a software plan drop-down list.
5. Click Create.

Prepare Azure Instance

Follow the steps below to provision the Azure VM hosting the Kemp LoadMaster load balancer.

1. Choose an Azure subscription to and resource group to deploy the resources to.
2. Provide instance details such as virtual machine name, region, availability options, and image size.
3. Select an authentication type and upload the SSH private key or provide a username and password.
4. Click Next:Disks >.

Always On VPN Load Balancing with Kemp in Azure

5. Select an OS disk type.
6. Click Next: Networking >.

Always On VPN Load Balancing with Kemp in Azure

7. Select a virtual network and subnet for the load balancer.
8. Create or assign a public IP address.
9. Click Review + create.

Always On VPN Load Balancing with Kemp in Azure

LoadMaster Configuration

Once the virtual machine has been provisioned, open a web browser and navigate to the VM’s internal IP address on port 8443 to accept the licensing terms.

Always On VPN Load Balancing with Kemp in Azure

Next, log in with your Kemp ID and password to finish licensing the appliance.

Always On VPN Load Balancing with Kemp in Azure

Finally, log in to the appliance using the username ‘bal’ and the password provided when the virtual machine was configured.

Always On VPN Load Balancing with Kemp in Azure

Azure Network Security Group

A Network Security Group (NSG) is automatically configured and associated with the LoadMaster’s network interface when the appliance is created. Additional inbound security rules must be added to allow VPN client connectivity.

In the Azure management console open the properties for the LoadMaster NSG and follow the steps below to configure security rules to allow inbound VPN protocols.

SSTP

1. Click Inbound security rules.
2. Click Add.
3. Choose Any from the Source drop-down list.
4. Enter * in the Source port ranges field.
5. Select Any from the Destination drop-down list.
6. Enter 443 in the Destination port ranges field.
7. Select the TCP protocol.
8. Select the Allow action.
9. Enter a value in the Priority field.
10. Enter a name for the service in the Name field.
11. Click Add.

Always On VPN Load Balancing with Kemp in Azure

IKEv2

1. Click Inbound security rules.
2. Click Add.
3. Choose Any from the Source drop-down list.
4. Enter * in the Source port ranges field.
5. Select Any from the Destination drop-down list.
6. Enter 500 in the Destination port ranges field.
7. Select the UDP protocol.
8. Select the Allow action.
9. Enter a value in the Priority field.
10. Enter a name for the service in the Name field.
11. Click Add.
12. Repeat the steps below for UDP port 4500.

Always On VPN Load Balancing with Kemp in Azure

Load Balancing SSTP and IKEv2

Refer to the following posts for detailed, prescriptive guidance for configuring the Kemp LoadMaster load balancer for Always On VPN load balancing.

Always On VPN SSTP Load Balancing with Kemp LoadMaster

Always On VPN IKEv2 Load Balancing with the Kemp LoadMaster

Always On VPN Load Balancing Deployment Guide for the Kemp LoadMaster

Summary

Although Windows Server RRAS is not a formally supported workload in Azure, it is still a popular and effective solution for Always On VPN deployments. The Kemp LoadMaster load balancer can be deployed quickly and easily to provide redundancy and increase scalability for larger deployments.

Additional Information

Windows 10 Always On VPN SSTP Load Balancing with Kemp LoadMaster Load Balancers

Windows 10 Always On VPN IKEv2 Load Balancing with Kemp LoadMaster Load Balancers

Windows 10 Always On VPN Load Balancing Deployment Guide for Kemp LoadMaster Load Balancers

Deploying the Kemp LoadMaster Load Balancer in Microsoft Azure

1 Comment

by Richard M. Hicks on November 4, 2019 • Permalink

Posted by Richard M. Hicks on November 4, 2019

https://directaccess.richardhicks.com/2019/11/04/always-on-vpn-load-balancing-with-kemp-in-azure/

Always On VPN Load Balancing for RRAS in Azure

Always On VPN Load Balancing for RRAS in Azure Previously I wrote about Always On VPN options for Microsoft Azure deployments. In that post I indicated that running Windows Server with the Routing and Remote Access Service (RRAS) role for VPN was an option to be considered, even though it is not a formally supported workload. Despite the lack of support by Microsoft, deploying RRAS in Azure works well and is quite popular. In fact, I recently published some configuration guidance for RRAS in Azure.

Load Balancing Options for RRAS

Multiple RRAS servers can be deployed in Azure to provide failover/redundancy or to increase capacity. While Windows Network Load Balancing (NLB) can be used on-premises for RRAS load balancing, NLB is not supported and doesn’t work in Azure. With that, there are several options for load balancing RRAS in Azure. They include DNS round robin, Azure Traffic Manager, the native Azure load balancer, Azure Application Gateway, or a dedicated load balancing virtual appliance.

DNS Round Robin

The easiest way to provide load balancing for RRAS in Azure is to use round robin DNS. However, using this method has some serious limitations. Simple DNS round robin can lead to connection attempts to a server that is offline. In addition, this method doesn’t accurately balance the load and often results in uneven distribution of client connections.

Azure Traffic Manager

Using Azure Traffic Manager is another alternative for load balancing RRAS in Azure. In this scenario each VPN server will have its own public IP address and FQDN for which Azure Traffic Manager will intelligently distribute traffic. Details on configuring Azure Traffic Manager for Always On VPN can be found here.

Azure Load Balancer

The native Azure load balancer can be configured to provide load balancing for RRAS in Azure. However, it has some serious limitations. Consider the following.

Supports Secure Socket Tunneling Protocol (SSTP) only.
Basic health check functionality (port probe only).
Limited visibility.
Does not work with IKEv2.
Does not support TLS offload for SSTP.

More information about the Azure Load Balancer can be found here.

Azure Application Gateway

The Azure Application Gateway can be used for load balancing RRAS SSTP VPN connections where advanced capabilities such as enhanced health checks and TLS offload are required. More information about the Azure Application Gateway can be found here.

Load Balancing Appliance

Using a dedicated Application Delivery Controller (ADC), or load balancer is a very effective way to eliminate single points of failure for Always On VPN deployments hosted in Azure. ADCs provide many advanced features and capabilities to ensure full support for all RRAS VPN protocols. In addition, ADCs offer much better visibility and granular control over VPN connections. There are many solutions available as virtual appliances in the Azure marketplace that can be deployed to provide RRAS load balancing in Azure.

Summary

Deploying Windows Server RRAS in Azure for Always On VPN can be a cost-effective solution for many organizations. Although not a formally supported workload, I’ve deployed it numerous times and it works quite well. Consider using a dedicated ADC to increase scalability or provide failover and redundancy for RRAS in Azure whenever possible.

Additional Information

Windows 10 Always On VPN Options for Azure Deployments

Windows 10 Always On VPN and RRAS in Microsoft Azure

Windows 10 Always On VPN with Microsoft Azure Gateway

9 Comments

by Richard M. Hicks on October 28, 2019 • Permalink

Posted by Richard M. Hicks on October 28, 2019

https://directaccess.richardhicks.com/2019/10/28/always-on-vpn-load-balancing-for-rras-in-azure/

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