Deployment Considerations for DirectAccess on Amazon Web Services (AWS)

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.

Deployment Considerations for DirectAccess on Amazon Web Services (AWS)

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.

Deployment Considerations for DirectAccess on Amazon Web Services (AWS)

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 not work 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 viable option. 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.

Deployment Considerations for DirectAccess on Amazon Web Services (AWS)

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 only supported 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.

Additional Resources

DirectAccess No Longer Supported in Microsoft Azure

Microsoft Server Software Support for Azure Virtual Machines

DirectAccess Network Location Server (NLS) Guidance

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

Provisioning DirectAccess Clients using Offline Domain Join (ODJ)

DirectAccess SSL Offload and IP-HTTPS Preauthentication with Citrix NetScaler

DirectAccess SSL Offload and IP-HTTPS Preauthentication with F5 BIG-IP

Planning and Implementing DirectAccess with Windows Server 2016 Video Training Course

Implementing DirectAccess with Windows Server 2016 Book

Migrating DirectAccess from NLB to External Load Balancer


Introduction

Migrating DirectAccess from NLB to External Load BalancerMultiple DirectAccess servers can be deployed in a load-balanced cluster to eliminate single crucial points of failure and to provide scalability for the remote access solution. Load balancing can be enabled using the integrated Windows Network Load Balancing (NLB) or an external physical or virtual load balancer.

NLB Drawbacks and Limitations

NLB is often deployed because it is simple and inexpensive. However, NLB suffers from some serious drawbacks that limit its effectiveness in all but the smallest deployments. For example, NLB uses network broadcasts to communicate cluster heartbeat information. Each node in the cluster sends out a heartbeat message every second, which generates a lot of additional network traffic on the link and reduces performance as more nodes are added. Scalability is limited with NLB too, as only 8 nodes are supported, although the practical limit is 4 nodes. Further, NLB supports only round-robin connection distribution.

External Load Balancer

A better alternative is to implement a dedicated physical or virtual load balancing appliance. A purpose-built load balancer provides additional security, greater scalability (up to 32 nodes per cluster), improved performance, and fine-grained traffic control.

Migrate from NLB to ELB

It is possible to migrate to an external load balancer (ELB) after NLB has already been configured. To do this, follow the guidance provided in my latest blog post on the KEMP Technologies blog entitled “Migrating DirectAccess from NLB to KEMP LoadMaster Load Balancers”.

Migrating DirectAccess from NLB to External Load Balancer

Additional Resources

DirectAccess Deployment Guide for KEMP LoadMaster Load Balancers

Migrating DirectAccess from NLB to KEMP LoadMaster Load Balancers

Load Balancing DirectAccess with KEMP LoadMaster Load Balancers

DirectAccess Load Balancing Tips and Tricks Webinar with KEMP Technologies

DirectAccess Single NIC Load Balancing with KEMP LoadMaster Load Balancer

Configuring the KEMP LoadMaster Load Balancer for DirectAccess NLS

Enable DirectAccess Load Balancing Video

Implementing DirectAccess with Windows Server 2016 Book

DirectAccess Load Balancing Tips and Tricks Webinar

KEMP Technologies LoadMaster Load BalancerEnabling load balancing for DirectAccess deployments is crucial for eliminating single points of failure and ensuring the highest levels of availability for the remote access solution. In addition, enabling load balancing allows DirectAccess administrators to quickly and efficiently add capacity in the event more processing power is required.

DirectAccess includes support for load balancing using integrated Windows Network Load Balancing (NLB) and external load balancers (physical or virtual). External load balancers are the recommended choice as they provide superior throughput, more granular traffic distribution, and greater visibility. External load balancers also more scalable, with support for much larger DirectAccess server clusters, up to 32 nodes. NLB is formally limited to 8 nodes, but because it operates at layer 2 in the OSI model and relies on broadcast heartbeat messages, it is effectively limited to 4 nodes.

The KEMP Technologies LoadMaster load balancer is an excellent choice for load balancing the DirectAccess workload. To learn more about configuring the LoadMaster with DirectAccess, join me for a free live webinar on Tuesday, August 16 at 10:00AM PDT where I’ll discuss DirectAccess load balancing in detail. I will also be sharing valuable tips, tricks, and best practices for load balancing DirectAccess.

DirectAccess Load Balancing Tips and Tricks Webinar

Don’t miss out. Register today!

Additional Resources

DirectAccess Load Balancing Overview

Load Balancing DirectAccess with the KEMP Loadmaster Load Balancer

Maximize your investment in Windows 10 with DirectAccess and the KEMP LoadMaster Load Balancer

KEMP LoadMaster DirectAccess Deployment Guide

Implementing DirectAccess with Windows Server 2016 Pre-Order

Update: My new DirectAccess book is now available for purchase. Details here.

I am pleased to announce that my new book, Implementing DirectAccess with Windows Server 2016 from Apress Media, is now available for pre-order on Amazon.com!

Implementing DirectAccess with Windows Server 2016

This book contains detailed and prescriptive guidance for the planning, design, implementation, and support of a DirectAccess remote access solution on Windows Server 2016. It also includes valuable insight, tips, tricks, and best practice recommendations gained from my many years of deploying DirectAccess for some of the largest organizations in the world.

Current DirectAccess administrators will also find this book helpful, as the majority of content is still applicable to DirectAccess in Windows Server 2012 and Windows Server 2012 R2. In addition, the book also includes essential information on the design and deployment of highly available and geographically redundant DirectAccess deployments.

Troubleshooting DirectAccess can be a daunting task, so I’ve dedicated an entire chapter in the book to this topic. For those responsible for the maintenance and support of DirectAccess in their organization, this chapter alone will be worth the investment.

Be sure to reserve your copy today!

DirectAccess Load Balancing Video

DirectAccess Load Balancing VideoConfiguring load balancing in DirectAccess is essential for eliminating single points of failure and ensuring the highest level of availability for the solution. The process of enabling load balancing for DirectAccess can be confusing though, as it involves the reassignment of IP addresses from the first server to the virtual IP address (VIP) for the cluster.

In this video I demonstrate how to enable DirectAccess load balancing and explain in detail how IP address assignment works for both Network Load Balancing (NLB) and external load balancers (ELB).

Configure Citrix NetScaler for DirectAccess NLS

DirectAccess and Citrix NetScaler WebinarIntroduction

The Network Location Server (NLS) is a crucial DirectAccess supporting infrastructure component. It is secure web server that DirectAccess clients use to determine if they are inside or outside of the corporate network.

NLS Availability

The NLS should be highly available. If this service is not available, DirectAccess clients on the internal network will think they are outside and attempt to establish a DirectAccess connection. Typically, this results in the DirectAccess client not being able to reach internal resources by hostname. Full connectivity for DirectAccess clients on the internal network will not be restored until the NLS is online.

It is recommended that the NLS be deployed in a load-balanced cluster for high availability. However, this requires deploying multiple servers, adding more cost, complexity, and management overhead to the solution.

NLS and Citrix NetScaler

Configuring the Citrix NetScaler to serve as the NLS is an attractive alternative to deploying additional servers for this role. Using the NetScaler for the NLS reduces costs by leveraging existing infrastructure. In addition, the NetScaler requires less servicing than a typical Windows server, and is often itself already highly available.

Configure Citrix NetScaler

To configure the NetScaler to serve as a DirectAccess NLS, open the NetScaler management console, expand AppExpert, and then select Actions. Click Add, provide a descriptive name for the responder action, and then enter the following in the Expression field and click Create.

"HTTP/1.0 200 OK" +"\r\n\r\n" + "DirectAccess Network Location Server (NLS)" + "\r\n"

Configure Citrix NetScaler for DirectAccess NLS

Select Policies, click Add, and then provide a descriptive name for the responder policy. Enter HTTP.REQ.IS_VALID in the Expression field and click Create.

Configure Citrix NetScaler for DirectAccess NLS

Expand Traffic Management, expand Load Balancing and select Services. Click Add, provide a descriptive name for the service, choose New Server, and enter the IPv4 loopback address 127.0.0.1. Select SSL for the Protocol, enter a random port number for the Port and then click More.

Configure Citrix NetScaler for DirectAccess NLS

Uncheck the box next to Health Monitoring and click Ok and Done.

Configure Citrix NetScaler for DirectAccess NLS

Select Virtual Servers and click Add. Provide a descriptive name for the virtual server, select SSL for the Protocol, enter an IP address for the virtual server and click Ok.

Configure Citrix NetScaler for DirectAccess NLS

Under Services and Service Groups click No Load Balancing Virtual Server Service Binding.

Configure Citrix NetScaler for DirectAccess NLS

Click to select a service, choose the service created previously and click Ok, Bind and Ok.

Configure Citrix NetScaler for DirectAccess NLS

Under Certificates click No Server Certificate.

Configure Citrix NetScaler for DirectAccess NLS

Click to select a server certificate, choose the SSL certificate to be used by the NLS and click Ok, Bind, and Ok.

Configure Citrix NetScaler for DirectAccess NLS

Under Advanced click Policies, and then click the + icon. From the Choose Policy drown-list choose Responder and click Continue. Click to select a Policy Binding and choose the responder policy created previously. Click Ok, Bind, and Done.

Configure Citrix NetScaler for DirectAccess NLS

Testing NLS Functionality

Open a web browser on a client connected to the internal network and browse to the NLS URL. Ensure that there are no certificate errors and that the NetScaler is responding with the configured web page.

Configure Citrix NetScaler for DirectAccess NLS

Summary

The Network Location Server (NLS) is an important, and often overlooked, supporting infrastructure component for DirectAccess. It is used by DirectAccess clients to determine their network location. If it is unavailable for any reason it can be very disruptive. Ensuring that the NLS is highly available is critical. Configuring the NLS on the Citrix NetScaler can be a cost-effective alternative to deploying additional servers, while at the same time reducing the chance of an outage due to NLS failure.

DirectAccess and Citrix NetScaler Webinar

DirectAccess and Citrix NetScaler Webinar

Updated 5/2/2016: The webinar recording is now available online here.

Join me on Tuesday, April 26 at 11:00AM EDT for a live webinar to learn more about integrating the Citrix NetScaler Application Delivery Controller (ADC) with Microsoft DirectAccess. During the webinar, which will be hosted by Petri IT Knowledgebase, you will learn how to leverage the NetScaler to enhance and extend native high availability and redundancy capabilities included with DirectAccess.

Eliminating single points of failure is crucial for enterprise DirectAccess deployments. DirectAccess includes technologies such as load balancing for high availability and multisite for geographic redundancy, but they are somewhat limited. DirectAccess supports integration with third-party solutions like NetScaler to address these fundamental limitations.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic ManagerNetScaler is an excellent platform that can be configured to improve upon native DirectAccess high availability and redundancy features. It provides superior load balancing compared to native Windows Network Load Balancing (NLB), with more throughput and better traffic visibility, while at the same time reducing resource utilization on the DirectAccess server.

For multisite DirectAccess deployments, the NetScaler can be configured to provide enhanced geographic redundancy, providing more intelligent entry point selection for Windows 8.x and Windows 10 clients and granular traffic control such as weighted request distribution and active/passive site failover.

DirectAccess and Citrix NetScaler WebinarIn addition, the NetScaler can be configured to serve as the DirectAccess Network Location Server (NLS), providing essential high availability for this critical service and reducing supporting infrastructure requirements.

Click here to view the recorded webinar.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Introduction

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic ManagerTo provide geographic redundancy, DirectAccess can be deployed in a multisite configuration. In this scenario, Windows 8.x and Windows 10 clients are aware of all entry points in the enterprise and will automatically select the nearest available entry point to connect to. The nearest entry point is defined as the one that responds the quickest. When a Windows 8.x or Windows 10 client attempts to establish DirectAccess connectivity, an HTTP GET is sent to all entry points and the client will select the one with the shortest Round Trip Time (RTT) for the request.

Note: Windows 7 clients can be provisioned when DirectAccess is configured for multisite access, but they must be assigned to an individual entry point.

Challenges

There are a number of challenges that come with the default multisite configuration. Choosing an entry point based solely on network latency is rather simplistic and can often produce unexpected results. It also lacks support for granular traffic distribution or active/passive configuration.

GSLB

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic ManagerFor the best experience, DirectAccess can be configured to use a Global Server Load Balancing (GSLB) solution to enhance transparent site selection and failover for Windows 8.x and Windows 10 clients. Commonly this is implemented using an on-premises appliance (Citrix NetScaler, F5 Global Traffic Manager, Kemp LoadMaster, A10 Thunder, etc.). These solutions offer exceptional control over DirectAccess traffic distribution, but they add expense and complexity.

Azure Traffic Manager

Azure Traffic Manager is a cloud-based GSLB solution that is a simple and cost-effective alternative to dedicated on-premises appliances. While it does not offer all of the features that GSLB appliances provide, it does provide better traffic distribution options than the default configuration. Importantly, it enables active/passive failover, which is a common requirement not supported natively with DirectAccess.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Traffic Manager Configuration

In the Azure portal (the new one, not the old one!) click New, Networking, and then Traffic Manager profile.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Provide a name and select a Routing method.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Routing method options are Performance, Weighted and Priority.

  • Performance. Select this option to enable clients to connect to the entry point with the lowest network latency.
  • Weighted. Select this option to enable clients to prefer some entry points more than others. Assign a weight value of 1 to 1000 for each entry point. Higher values have more preference. Values for entry points can be the same, if desired.
  • Priority. Select this option to enable clients to connect to a primary entry point, then fail over to a secondary or tertiary entry point in the event of an outage. Assign a priority value of 1 to 1000 for each entry point. Lower values take precedence. Each entry point must be assigned a unique priority value.

Click Create when finished. Next click Settings for the new traffic manager profile and click Configuration. Change Protocol to HTTPS, Port to 443, and Path to /IPHTTPS. Click Save when finished.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Next click Endpoints and click Add. Select External endpoint from the drop down list, provide a descriptive name, and then enter the Fully-Qualified Domain Name (FQDN) of the first DirectAccess entry point. When using the Performance routing method, choose a location that best represents the geography where the DirectAccess entry point is located. When using the Weighted or Priority routing methods, specify an appropriate value accordingly. Click Ok when finished. Repeat these steps for each entry point in the organization.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

DirectAccess Configuration

In the Remote Access Management console, highlight DirectAccess and VPN below Configuration in the navigation tree and then click Configure Multisite Settings below Multisite Deployment in the Tasks pane. Click Global Load Balancing and choose Yes, use global load balancing. Enter the FQDN of the Azure Traffic Manager profile and click Next, and then click Commit.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

Note: An SSL certificate with a subject name matching that of the GSLB FQDN is not required.

In some cases, the management console may report that global load balancing addresses cannot be identified automatically for some or all entry points.

DirectAccess Multisite Geographic Redundancy with Microsoft Azure Traffic Manager

If this occurs, it will be necessary to run the Set-DAEntryPoint PowerShell cmdlet to assign GLSB IP addresses to each entry point. The GSLB IP address is the public IPv4 address that the entry point public hostname resolves to.

Set-DAEntryPoint -Name [entrypoint_name] -GslbIP [external_ip_address]

For example:

Set-DAEntryPoint -Name "US West" -GslbIP 203.0.113.195
Set-DAEntryPoint -Name "US East" -GslbIP 198.51.100.21

Summary

DirectAccess includes native functionality to enable geographic load balancing for Windows 8.x and Windows 10 clients. The site selection process used by DirectAccess clients in this scenario is basic, and has the potential to yield unexpected results. Azure Traffic Manager is a simple, cost-effective alternative to dedicated on-premises GSLB appliances. It can be integrated with DirectAccess to address some of the shortcomings with the native entry point selection process.

Additional Resources

Configuring Multicast NLB for DirectAccess

Introduction

DirectAccess in Windows Server 2012 R2 includes support for load balancing using either Windows Network Load Balancing (NLB) or an external physical or virtual load balancer. There are advantages and disadvantages to each, but NLB is commonly deployed due to its cost (free!) and relative ease of configuration. NLB has three operation modes – Unicast, Multicast, and IGMP Multicast. It may become necessary to change the NLB operation mode depending on the environment where DirectAccess is deployed. This article describes when and how to make those changes.

Default Configuration

When NLB is first configured, the default cluster operation mode is set to Unicast. In this configuration, all nodes in the NLB cluster share the same MAC address. The NLB kernel mode driver prevents the switch from learning the MAC address for any node in the cluster by masking it on the wire. When a frame is delivered to the switch where the NLB cluster resides, without a MAC address to switch port mapping the frame is delivered to all ports on the switch. This induces switch flooding and is by design. It is required for all nodes in the cluster to “see” all traffic. The NLB driver then determines which node will handle the request.

NLB on Hyper-V

Unicast NLB typically works without issue in most physical environments. However, enabling NLB when the DirectAccess server is running on a virtual machine requires some additional configuration. For Hyper-V, the only thing that is required is to enable MAC Address Spoofing on the virtual network adapter as I discussed here. No other changes are required.

NLB on VMWare

For VMware environments, it will be necessary to change the cluster operation mode from unicast to multicast. This is because the VMware hypervisor proactively informs the virtual switch of the virtual machine’s MAC address on startup and during other virtual networking events. When this occurs, all traffic for the NLB Virtual IP Address (VIP) will be delivered to a single node in the cluster. In multicast operation mode, all nodes in the NLB cluster retain their original MAC address and a unique MAC address is assigned to the cluster VIP. As such, there’s no need to prevent the switch from learning the virtual machine’s MAC address.

Configuring Multicast NLB

To enable Multicast NLB, first enable load balancing for DirectAccess using the Remote Access Management console as usual. DO NOT perform the initial configuration of NLB outside of the Remote Access Management console! Before adding another member to the array, open the Network Load Balancing Manager, right-click the cluster and choose Cluster Properties. Select the Cluster Parameters tab and change the Cluster operation mode to Multicast.

Configuring Multicast NLB for DirectAccess

When opening the Network Load Balancing Manager locally on the DirectAccess server, you may receive the following error message:

“Running NLB Manager on a system with all networks bound to NLB might
not work as expected. If all interfaces are set to run NLB in “unicast”
mode, NLB manager will fail to connect to hosts.”

Configuring Multicast NLB for DirectAccess

If you encounter this error message it will be necessary to run the NLB Manager on another host. You can install the NLB Manager on a Windows Server 2012 R2 system by using the following PowerShell command.

Install-WindowsFeature RSAT-NLB

Optionally you can download and install the Windows Remote Server Administration Tools (RSAT) on a Windows desktop client and manage NLB remotely.

Once this change has been made you can add additional DirectAccess servers to the array using the Remote Access Management console.

Additional Configuration

If you cannot communicate with the cluster VIP from a remote subnet, but can connect to it while on the same subnet, it might be necessary to configure static ARP entries on any routers for the subnet where the NLB cluster resides. Often this is required because routers will reject responses to ARP requests that are from a host with a unicast IP address but have a multicast MAC address.

WEBINAR: Maximize Your Investment in Windows 10 with DirectAccess and the Kemp LoadMaster

Kemp Technologies LoadMaster Load BalancerWith the recent release of Microsoft’s Windows 10 client operating system, many organizations are now planning their migration to Windows 10 from previous versions. For those organizations looking to maximize their investment in Windows 10, many are considering the deployment of DirectAccess with Windows Server 2012 R2.

DirectAccess and Windows 10 - Better TogetherDirectAccess and Windows 10 are much better together. Windows 10 includes full support for all of the important enterprise features of DirectAccess in Windows Server 2012 R2, including geographic redundancy, transparent site selection, and IP-HTTPS performance improvements. The Kemp LoadMaster load balancer can be used to extend and enhance the native high availability features of DirectAccess, and it can be used to reduce supporting infrastructure requirements.

To learn more about maximizing your investment in Windows 10 with DirectAccess and the Kemp LoadMaster load balancer, be sure to attend our upcoming webinar on Thursday, October 15 when I’ll discuss in detail and demonstrate the advantages of Windows 10 and the Kemp LoadMaster load balancer.

You can register for the Windows Server 2012 R2 DirectAccess and Kemp Technologies LoadMaster webinar here.

Kemp Technologies LoadMaster Load Balancer

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