Load Balancing the RD Connection Brokers with KEMP


This post will show you how to configure the load balancing of RDS 2012 Connection brokers. For the configuration of RD Connection broker high Availability please see the following article (here)

Before we get started with the configuration of the KEMP LoadMaster, I have included some information on other load balancing solutions and why its important to use a Hardware/Software load balancers.

Why you should not use DNS Round Robin

Round Robin DNS (RRDNS) distributes workload among multiple servers but does not provide a mechanism for server availability. If a server within the host fails, RRDNS, unlike Hardware Load Balancing,  will continue to send traffic until a network administrator detects the failure and removes the server from the DNS address list. This results in service disruption for clients.

Why you should not use Network Load Balancing (NLB)

  • Windows Network Load Balancing is limited to a maximum number of 32 possible hosts in any one cluster
  • Load calculations are only based on the network load and Server response time
  • All hosts must be in the same subnet
  • Each Server Shares the same IP address
  • offers basic layer 4 load balancing functionality

Configuring Remote Desktop Connection broker High Availability with KEMP

If you Haven’t already implemented RDCB HA, I would suggest that you configure the KEMP Loadmaster first.

If you are migrating from DNS Round Robin over to KEMP, I would recommend that you add an additional DNS record for the KEMP Loadmaster (run parallel) and once configured remove the old records.

The Connection broker communicates with other connection brokers using the service port 3389.

Create the virtual Service and Set the port to 3389.

Virtual Service

RD CB HA

Enter in the Service Name, select the service type “Remote Terminal”

Under standard options, you will need to ensure that transparency is turned off and that persistence settings are set to “Terminal Service or Source IP” and a time out of “6 minutes”.

The Connection Broker role does not rely on persistence, this is because it handles the initial RDP request and does not contain any active sessions. You could use any option but KEMP recommend that you use the default.

Set the Scheduling Method to “Round Robin” and the Idle connection timeout to “Blank” seconds

Round robin is the best suited scheduling method as this ensures that load is equally spread over the RD Connection Brokers. You can also use weighted Round Robin if the real servers have a none-default weight set.

Health Checking

Set the Real Server check parameters to “Remote Terminal Protocol” Checked Port “3389”

“Ensure that you have added the KEMP Virtual Service A Record to DNS and if using DNSRR, ensure you have removed the old records”

There you have it ! RDS Connection Broker High Availability Load Balanced with  a KEMP Loadmaster.

5 thoughts on “Load Balancing the RD Connection Brokers with KEMP

  1. hi, Ryan.
    I have Windows Server Terminal Farm 2012 R2 and KEMP Loading Balansing. I am trying to configure Load Balancing the RD Connection Brokers with KEMP.
    And i have double load balancing: at first Kemp does balancing, after that it does RD Connection Brokers. And i know i need disable loading balancing on Microsoft Terminal Farm, but i don’t know how. Do you have the necessary experience?

  2. RDP services are configured for Load balancing. So I configured two windows server 2012r2 and deployed RD session host roles. I have connection broker role without hight availability mode. And i configured sessions collection which already have its own load balancer .
    I configured KEMP in persistent mode = connection broker, Scheduling Method = least connection (other settings are default)
    So we have two load balancers: one for KEMP and one for session collection. And i dont know how to disable session collection load balancer. There a way to disable collection session load balancer in Windows 2012 R2?
    I need it disable because load balancing in sessions collection does final balancing.
    In 2008R2 there was the option for disable this function (Participate in Connection Broker Load-Balancing).

  3. Ryan, first of all many thanks for taking the time to blog all these configuration posts …. extremely useful for me as I am trying to scale a small RDS test environment up in to Azure and separate roles out.
    I have been looking at how I can utilise Kemp load balancers in the environment too. If I were to balance out connections to the web access and connection broker server roles would you suggest using separate balancers.
    At the moment it will be internal connections up to Azure only with an external gateway in to the environment later.
    I also noted you advise configuring any Kemp LB for the connection brokers prior to doing the SQL HA …. how important is this step ??
    Any help or advice very much appreciated

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