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KEMP’s LoadMaster family of affordable, yet feature rich application delivery controllers and server load balancer appliances automatically and intelligently manage user traffic and applications, to deliver website integrity for small-to-medium sized businesses (SMB) and managed service providers.

KEMP LoadMaster is an hardened Linux appliance that provide several features:

  • Server Load Balancing for TCP/UDP based protocols
  • NAT-based forwarding or Direct Server Return (DSR) configurations
  • Layers 4-7 Load Balancing
  • Layer 7 Content Switching
  • Server Persistence
  • Windows Terminal Services load balancing and persistence with Session Directory integration
  • SSL Termination/Offload/Acceleration
  • Application Front-end (Caching, Compression and IPS security)
  • Advanced, App-Transparent Caching Engine for HTTP/HTTPS protocols
  • Optimized Compression for Static and Dynamic HTTP/HTTPS Content
  • Layer 7 Intrusion Prevention System (IPS), SNORT-Rule (HTTP) Compatible
  • Configurable S-NAT support
  • Web User Interface (WUI) for easy administration & configuration
  • Industry leading price/performance value
  • Supports cloning and relocating with native Virtualization Framework management tools

The load balancing is based on a customized version of Linux Virtual Server. But several other deaemons implement features like proxy, L7, IDS, …

There are both physical and virtual version of the appliance (see also the full comparison). For the virtual edition the main difference is:

  • VLM-100: Max. 100 Mbps Throughput, max. 100 SSL TPS, everything else unrestricted. Actual performance will depend on allocated resources to Virtual Machine.
  • VLM-1000: Up to 1000 SSL TPS, everything else unrestricted. Actual performance will depend on allocated resources to Virtual Machine.

Note that there are several distributors, but also some big hardware vendors sell KEMP solution (for example see this page on the Dell Accessories catalog… maybe a sign for a possible future acquisition?)

Why a load balancer?

For enterprise architecture, a load balancer is the external solution needed to provide a better availability (and scalability) level for a service. Actually several services may require a load balancer in their architecture, for example:

  • VMware View: require load balancers both for the Security Servers and the View Connection Servers
  • Exchange: require load balancers for some roles, like the CAS
  • Terminal Server/RDS Host: although it can use the Windows solution (NLB), it can use also external load balancers.


This could be a good question, especially for the virtual appliance. There are already a lot of similar solutions (some also free) and also VMware has some similar appliance integrated with vSphere (vShield Zones /vShied Edge).

One simple reason could be that most of the appliance are most firewall oriented (included vShield solutions), with really limited feature at load balancing side. In most cases they can still can be used just for the firewall part. VLM focus is on load balancing, that mean also several paper and documentation and recommendation for different type of application (for example, for Exchange see: Differences in Exchange Load Balancing recommendations by Microsoft and vendors).

The other features covered by VLM are usually the complementary part, like SSL acceleration, proxy, application check and protection, … and this make the KEMP solution a good appliance for all applications that need those services.

Finally there could be also the reason related to the platform: actually KEMP support both VMware and Hyper-V and this could be good value in multi-hypervisors enviroments.


Virtualization, Cloud and Storage Architect. Tech Field delegate. VMUG IT Co-Founder and board member. VMware VMTN Moderator and vExpert 2010-24. Dell TechCenter Rockstar 2014-15. Microsoft MVP 2014-16. Veeam Vanguard 2015-23. Nutanix NTC 2014-20. Several certifications including: VCDX-DCV, VCP-DCV/DT/Cloud, VCAP-DCA/DCD/CIA/CID/DTA/DTD, MCSA, MCSE, MCITP, CCA, NPP.