"Cook Book": First steps configuring a LoadMaster installation

Who likes reading manuals...? 

Here are 3 simple examples to make installation work with the new LoadBalancer:

  • Load Balancing for Web servers
  • Load Balancing with SSL-Offloading (SSL acceleration) for SSL-web server
  • Load Balancing for Windows Terminal Server.

You can of course try all this with the free LoadBalancer using VMware / Hyper-V. http://www.kemptechnologies.com/try

Starting point is a ready-to-use LoadMaster. If you need to get your LoadMaster server working using VMware or similar, please refer to the “Cook book” article VLM configuration.


Load Balancing for Web Server

Click on “Add New” under “Virtual Services”. Enter the designated IP-address for the new service (Virtual Service). This needs to be in the same IP network as the LoadMaster interface.


  • My test LoadMaster has the IP on eth0 (Meaning that this is the address I use to manage it. For HA-pairs this would be the shared IP).
  • Therefore my virtual service IPs need to be 192.168.69.x. For Example:

Perspective: Virtual services can be mapped to eth1, eth2 and so forth.  Even alias addresses can be managed by the LoadMaster server. So several IP networks can be used for virtual services.


The configuration screen of the new virtual service will appear now.

Please change the following settings:

  • Switch off L7 Transparency
  • Switch persistency to “Active Cookie or Source IP”, which usually is my favourite setting.
  • Set persistency timeout to 1 hour (Persistency net mask can be left at /32, its not related to the local IP sub net).
  • Change scheduling to “Weighted last Connections” – this is also the standard recommendation.


Now give the server a name to keep things nice and tidy.


Next allocate the web server (“Real Server”) to this virtual service.



Here the web server (“Real Server”) needs to be in the same local network as the LoadBalancer. (Perspective:  this could be configured differently in exceptional cases....)

Now repeat those steps for all other web servers:


Ready? Then hit “Back” to the Virtual Service...


... where you can see all Real Server listed:


Click “View/Modify” to check the settings. You will see a list of all Virtual Services.  This is one of the most important pages while the system is productive.

In this example configuration a real server has been added which is not active at the moment. Promptly it shows up in red. Meanwhile the Virtual Service would send all requests to the other real server – therefore still showing green. That’s how it should be.


To check, that it all works, try to access the IP of the virtual service with your browser.


Load Balancing with SSL Offloading for SSL-Web Servers

Now we want to publish our existing web server using HTTPS (using SSL) – more precisely:  We keep the web server settings, but the Loadmaster shall represent them externally via SSL. At the same time this will produce the so called SSL Acceleration.

Let’s start: We configure a new virtual service, which can have the same IP as before, but this time using the HTTPS-port 443.



Leave the basic configuration as before, just change the “nickname”. Activate the “Enabled” box for “SSL Acceleration”.


A pop-up window should appear, indicating that a temporary SSL-Certificate will be used. This can be replaced by an official certificate later (issued by VeriSign, Thawte&Co.)


After confirmation the SSL Properties should look like this:


Now enter the Real Servers EXACTLY as in the previous chapter – thus using port 80, because our real web servers do not “know” about SSL.


That’s it.

Testing the new features accessing the new Service (don’t forget https://) a browser warning will show, indicating we haven’t installed an official certificate yet.


Confirming the warning your webpage will show using HTTPS:



Load Balancing for Windows Terminal Server

In this last chapter we will move away from the web servers and have a look at the subject of load balancing for terminal servers, using the Remote Desktop Protocol (RDP).

You will see that most of the steps will be repetitive.

Let’s start with “Add New”. We need to know that PDP works using TCP-port 3389.


Again the LoadMaster recognizes which protocol is used and changes some default settings. Everything else seems familiar by now...

However we will assume a higher “Persistence Timeout”, which could make sense for a Terminal Server.


Perspective: Instead of “Weighted Last Connection”,  KEMP’s “Adaptive Balancing” is especially useful for Terminal Servers.

Now enter the Real Server using the proper port 3389.

RS-list (1).png

Again that’s it.

Now test the features using a remote desktop client of your choice.

Perspective: Technical details can be found on the KEMP documentation website http://www.kemptechnologies.com/documentation , Load Balancing Microsoft Terminal Service Guide ; http://www.kemptechnologies.com/fileadmin/content/downloads/documentation/4.3/Load_Balancing_Microsoft_Terminal_Services.pdf

Next steps

Let’s have a look at the Virtual Services you have installed:

VS-list (1).png

In this article we looked only at a few examples. Of course there are hundreds more. There are a lot of users running hundreds of Virtual Services on the same LoadMaster, often of the same type (for example 50 SSL-websites simultaneously).
You can find a lot of tips and tricks on this page and the web about different applications like Exchange 2010, SharePoint, DNS, MySQL, Citrix, SAP and many more. In general the questions and answers are recurring and you can work them out yourself with some basic understanding.
Browsing the KEMP manuals; http://www.kemptechnologies.com/documentation can’t be any harm.

The same is true for application independent subjects as topology, transparency, persistency, monitoring, data protection and many more.

There are also more unusual aspects and news about which we will keep you updated on these pages.

The next “cook book” article will concentrate on the subject of LoadMaster fine tuning including a check list of the 10 most important items to consider.

This manual is based on the LoadMaster Firmware Version 5.1-45.


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