Free Fault Tolerant Load Balancing using Citrix NetScaler Express (Part 3)

• Free Fault Tolerant Load Balancing using Citrix NetScaler Express (Part 1)
• Free Fault Tolerant Load Balancing using Citrix NetScaler Express (Part 2) - Citrix StoreFront/Web Interface and XML Broker

Microsoft Remote Desktop Web Access

       Figure 1: Adding Servers

Within the Create Server window we need to specify the server name and the corresponding IP address. Logically you need to redo this step for all the servers that will be part of the load balance group. For this article I will add two servers, VBN-SRV016 (192.168.21.216) and VBN-SRV017 (192.168.21.217).

                          Figure 2: Create Server window

In another scenario we would set-up a monitor to check if the service is still responding. However the RD Web Access is just plain HTTP/HTTPS traffic. Within NetScaler these monitors are already available by default so we don’t need to create one and we can directly continue with creating the services. The services are created at Traffic Management – Load Balancing – Service again within the Configuration tab. Again use the Add button to set-up the service.

      Figure 3: Create Services

Provide a logical name for the Service Name. I use RDWASRV_<> as a naming convention. Because we already added the server ealier, we can select existing server and select the server in the drop-down box. Choose the corresponding protocol. As I used HTTP in the previous article, I will now use a secured connection. For HTTPS you select SSL_BRIDGE and the corresponding port (by default 443).

                                Figure 4: Basic Settings Load Balancing Service

After pressing OK the service is created. After that we are changing the monitor binding. Select the > symbol at the end of 1 Service to Load Balancing Monitor Binding.

       Figure 5: Load Balance Service created, changing monitors

By default the tcp-default monitor is bind to a service, to change this default behavior choose Add Binding.

      Figure 6: Service Load Balancing Monitor Binding

Click the > symbol at the Select Monitor option.

               Figure 7: Selecting Monitor Binding

A list of available monitors will be shown. Select the monitor HTTPS.

      Figure 8: Select https monitor

Leave the other settings default and choose the Bind button.

                    Figure 9: https monitor selected

Now the Load Balancing Service is fully configured. Repeat these steps for the other servers that will be part of the load balancing infrastructure.

    Figure 10: https monitor selected

After the creation of the services, we are ready to set-up the actual virtual server which will be the access point of the RD Web Access users. To set-up the virtual server go to Configuration then Traffic Management – Load Balancing – Virtual Servers and start the process via the Add button.

         Figure 11: Virtual Servers

Provide a name for the virtual server. Again you name it whatever you like, but a name that explains the functionality makes sense over time. Select  protocol SSL_BRIDGE as Protocol and IP Address as IP Address type. Next you need to enter the IP address for the virtual server, followed by providing the port number the virtual server will be accessed.

                              Figure 12: Create Virtual Server

When the OK button is pressed, the virtual server will be created. After, the creation services should be assigned to this virtual server. Choose the > symbol after No Load Balancing Virtual Service Binding.

       Figure 13: Add services after virtual server creation

Press the > symbol at Select Service to add services to the virtual server.

                              Figure 14: Select Service Binding

A list of configure services is shown. Pick the services you have just configured for this virtual server. In my case these are VBN-SRV016 and VBN-SRV017.

   Figure 15: Select the required services

The services are now selected and can be connect to the virtual server using the Bind button.

                                    Figure 16: Service Binding selected

After binding the services persistance is automatically configured on SSLSESSION. If required you can change the persistance setting using the pencil icon, but this is optional.

      Figure 17: Virtual Server configuration finished

The last step is to create a DNS record to the Virtual Server IP address. For this article I created this for internal access, so I can add it to my local DNS.

                              Figure 18: Creating DNS record for the virtual server

 

Microsoft Remote Desktop Connection Broker

                 Figure 19: RDP monitoring available within the NetScaler, but cannot be used for the RD Connection Broker

So we can skip the monitor part for this component and directly start creating the services for the RD Connection Broker role. Go to Traffic Management – Load Balancing – Services within Configuration followed by the Add button.

           Figure 20: Load Balancing - Services

Provide a logical name for the service. I’m using the convention RDCBSRV_<>, but you can fill in whatever you need. As we already added the servers earlier we now can choose the existing server option and select the corresponding server. Next select RDP as the protocol with port 3389.

         Figure 21: Add Load Balancing Service

When the service is created we normally add a specific monitor, but as just mentioned there is no monitor available. The only option available is using the default tcp-default monitor, which checks that port 3389 is responding. Repeat this step for the other servers hosting the RD Connection Broker role.

   Figure 22: No specific monitor needs to be added

After pressing the Done button the service is fully created and is available for the next step - creating the virtual server.

        Figure 24: Creating Virtual Servers

Creating the Virtual Server starts with providing a name for the virtual server. This name is just for administrative purposes, so fill in a logical name. Secondly the protocol needs to be set to RDP and use IP address as IP Address type. Fill in the IP address the virtual server will be accessed to. At last check if the port number is port 3389.

      Figure 23: Services created

Creating the Virtual Server is done via Traffic Management – Load Balancing – Virtual Servers again within the Configuration tab.

              Figure 25: Create Load Balancing Virtual Server

After the basic settings we need to assign the corresponding services to the virtual server. Choose the > symbol at No Load Balancing Virtual Service Binding.

       Figure 26: Basic Settings Virtual Server, add services

The Service Binding window will open. Select the > symbol to select the services.

          Figure 27: Select Service

Select the services that are hosting the role.

      Figure 28: Select the services

The services are now selected and available to bind to the virtual server.

                    Figure 29: Services to bind to the virtual server

After adding the services, we need to use the OK button to continue with the next step.

      Figure 30: Service binded, press OK for the next step

After pressing OK the Traffic Settings appear, just accept the default values by pressing Done.

       Figure 31: Traffic Settings are set

After some time the Virtual Server will be changed to green and is load balancing service available.

     Figure 32: Virtual Server is up and running

To make sure that settings are retained when a NetScaler is reboot, don’t forget to save your configuration using the floppy disk icon.

                                    Figure 33: Saving the configuration

The last step is to create a DNS record so the service can be reached on a FQDN. Choose a logical name and assign it to the IP address of the Virtual Server. Remember that this FQDN needs to be configured within the RD Connection Broker configuration, so use the same name you are already using (that will probably change the DNS records) or write down the FQDN and use this in the RDCB wizard.

 

Remote Desktop Gateway

 

Summary