WSD Pro is configured using an SNMP-based application called Config Master. Noticeable changes in the layout and functionality of the Config Master software in the past year assist in every aspect of WSD Pro's configuration. Similar to the IronView program for Foundry Networks' ServerIron, Config Master handles all configuration of the WSD Pro after basic IP information has been configured via a serial interface. Although there's no command-line interface or telnet access to WSD Pro, the Config Master software for Windows95/NT does a fine job for all necessary configuration and management. You can also view and record SNMP traps using the Config Master interface.

WSD Pro's standout feature is its ability to act as both a primary and secondary load balancer at once. When a pair of WSD Pros serves more than one cluster, one WSD Pro can act as a primary load balancer for the first cluster while the other WSD Pro takes the secondary role.

These roles are reversed for the second cluster. No cabling is required to establish the redundant relationship, and all backup information is exchanged over the network. Identical configurations for each WSD Pro are required for the backup to work properly, but each must be configured individually. During normal operation, the primary and secondary units simply serve their respective Web clusters until one of the two load balancers fails.

To put the WSD Pro's redundancy features to the test, we created a second test cluster and serviced it using the secondary WSD Pro. Subsequent tests validated RND's claims, as both the primary and secondary load balancers assumed each other's roles and responsibilities during failure. The vendor justifies the additional cost of the second unit by giving you increased functionality for your dollar. The WSD Pro enables you to use all devices all the time, a claim rivals such as ServerIron, BIG/ip³, Hydra5000 and LocalDirector can't match.

The WSD Pro also has a complete set of informative, real-time monitoring tools, second only to those of Resonate Central Dispatch. Using Config Master, we were able to monitor each real server's user load, peak frame rate and load.

There's no limit to the number of servers you can monitor, allowing network administrators quick access to all available statistics. The WSD Pro also supports multiple networks via two or four Fast Ethernet ports--unmatched in this market. Virtual servers also can be monitored to determine aggregate server load and usage. In short, WSD Pro is without a doubt the most refined hardware load balancer we tested.

Foundry Networks ServerIron 3.05
One of two newcomers to the load-balancer scene, ServerIron makes a splash with unique features and above-average performance for a hardware-based load balancer. A member of Foundry Networks' Iron line of routers and switches, ServerIron provides eight to 16 ports of load-balancing nirvana. Outstanding redundancy options such as nonserial failover connection and multiple configuration interfaces put ServerIron close to the top of the load balancers we tested. Factor in its strong performance and low price, and you've got a solid solution.

Using the accompanying IronView management software, we were able to make quick changes to our Web clusters and real servers. IronView is almost as efficient for managing the load balancer as WSD Pro's Config Master software, but ServerIron lacks the configuration options found in WSD Pro. For those who still live by the command-line interface, ServerIron can be configured via telnet or serial connections. Although we were able to view each ServerIron status from the console interfaces, we could not determine which ServerIron was primary and which was secondary from within IronView. But a Web management interface is one of a kind, allowing for remote access to most configuration options.