Kemp Technologies LoadMaster X15 review: Perfectly balanced, as all things should be

Kemp’s latest hardware ADC is big on performance and remarkably small on price

IT Pro Verdict

SMEs looking for a well-specified hardware ADC that delivers on performance and features won’t find a more affordable alternative to Kemp’s LoadMaster X15


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    Superb value; Easy deployment; Top performance; Good load balancing features; High port density; 10GbE-enabled


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    WAF scanning can be resource intensive

There may be a huge range of choices in the load balancer, or application delivery controller (ADC), market but Kemp Technologies has always stood out with its ability to deliver some of the most affordable solutions. The LoadMaster X15 on review is a fine example: this hardware ADC offers an impressive range of features and performance at a price few others will be able to match, let alone beat.

It's no lightweight either. This 1U rack appliance offers 16 copper Gigabit ports and four SFP+ fibre 10-Gigabit ports. Designed for businesses that want an ADC with a high port density, the X15 allows them to deploy multiple server farms on different subnets and implement functions such as VLAN separation.

The X15 delivers a remarkable performance for the price, boasting a high L4 traffic throughput of 15.8Gbps. It can handle up to 35 million L4 concurrent connections while its ASIC-based SSL acceleration is good for up to 12,000 TPS (transactions per second) with 2K keys.

It's no surprise that performance is this good as the X15 is powered by a 3.8GHz Intel Xeon E3-1275 v6 CPU partnered by 32GB of 2,400MHz DDR4 memory. All storage is handled by a mirrored pair of 500GB SFF hard disks while a Cavium Nitrox III PCI-Express card manages SSL acceleration.

Kemp Technologies LoadMaster X15: Deployment options

For installation, you can use a CLI (command line interface) connection, connect a local monitor and keyboard or point a browser at the appliance's default IP address. We chose the latter and after applying a license file were ready to go in 10 minutes.

The X15 supports both single-arm and two-arm network deployments where the former requires all physical and virtual servers to be on the same subnet. It only uses port Eth0 but this can be made up of a bonded link taken from any of the physical ports. The two-arm mode allows all ports to be used individually and places physical and virtual servers on separate subnets.

The web interface sees a welcome redesign and opens with a summary page showing the status of physical and virtual servers along with a table of throughput for all network interfaces. More information is available in the statistics page, where we could view real-time performance charts of appliance hardware and pull up historical graphs of utilisation going back a year.

Kemp Technologies LoadMaster X15: Virtual servers and SDN

All LoadMasters adhere to the standard concepts for server load balancing. The X15 employs virtual servers to intercept web traffic and these are assigned to farms of physical servers where load balancing is carried out across all members.

Virtual servers are simple to create; we provided an IP address, port number and protocol and then added physical servers to our farms. Kemp offers nine load balancing, or scheduling, methods including round robin, weighted round robin, least connections and weighted response modes.

Kemp has software defined networks (SDNs) covered as its SDN Adaptive schedule allows the X15 to poll SDN controllers for performance and status metrics and use them for load balancing. It just requires a couple of small add-ons to be downloaded and applied and then you can define SDN controller addresses and use parameters such as real server port statistics and relative bandwidth for intelligent application delivery.

Kemp Technologies LoadMaster X15: Persistence and security

Layer 4 connection persistence uses source and destination addresses to ensure traffic from a particular client is always sent to the same physical server. Layer 7 connection persistence methods include cookies, session IDs and URLs while L7 content switching rules allow the X15 to optimise traffic based on web content.

The Enterprise subscription activates the embedded Snort database to provide IPS protection and intrusion alerting for physical servers. This also enables the Web Application Firewall (WAF) pack which provides enhanced protection of critical apps while the Enterprise Plus subscription includes daily rule updates.

WAF rules can be applied to virtual servers during creation or on-demand and range from IP reputation checks and malware detection to specific attacks on apps such as SharePoint and OWA. However, don't get too carried away as WAF rules inspect every incoming packet and can be very resource hungry.

Kemp Technologies LoadMaster X15: Remote management

Businesses with multiple LoadMasters will love Kemp's 360 Central as they can manage them all from one console. We tested the Hyper-V version and had it loaded in 15 minutes with the X15 declared to it shortly afterwards.

The web console opens with a dashboard showing all monitored ADCs along with status charts for overall device health, licensing, the top three most utilised ADCs, a log summary plus all virtual and physical servers and WAF statistics.

The free version of 360 Central provides all these monitoring services along with configuration backups and remote ADC reboot features. The Enterprise and Plus subscriptions enable full ADC management where you can remotely configure real and virtual servers and apply templates.

The 360 Vision cloud service also links up with Kemp's helpdesk and support teams to provide ADC monitoring and advanced warning on detected issues, along with sage advice on remedial actions. It required a local agent loaded as a Hyper-V VM, after which we declared our ADCs to it as new clusters and set our email address as the preferred communication channel (it also supports Slack and SMS).

Kemp Technologies LoadMaster X15: Verdict

During testing, we found the LoadMaster X15 easy to deploy and were impressed with the level of load balancing features. It offers a high port density and is exceptionally good value -- you'll be hard-pushed to find alternative hardware ADC solution that delivers the same high performance at this low price.


SMEs looking for a well-specified hardware ADC that delivers on performance and features won’t find a more affordable alternative to Kemp’s LoadMaster X15

Chassis: 1U rack

CPU: 3.8GHz Intel Xeon E3-1275 v6

Memory: 32GB 2,400MHz DDR4

Storage: 2 x 500GB mirrored SFF hard disks

Network: 16 x Gigabit, 4 x 10GbE SFP+

Other Ports: VGA, serial, 2 x USB

SSL Acceleration: Cavium Nitrox III CN3530 PCI-e card

Power: 2 x 450W hot plug PSUs

Management: Web browser, 360 Central

Subscriptions: Enterprise, £2,206 per year, Enterprise Plus, £3,346 per year

Dave Mitchell

Dave is an IT consultant and freelance journalist specialising in hands-on reviews of computer networking products covering all market sectors from small businesses to enterprises. Founder of Binary Testing Ltd – the UK’s premier independent network testing laboratory - Dave has over 45 years of experience in the IT industry.

Dave has produced many thousands of in-depth business networking product reviews from his lab which have been reproduced globally. Writing for ITPro and its sister title, PC Pro, he covers all areas of business IT infrastructure, including servers, storage, network security, data protection, cloud, infrastructure and services.