Load balancer discovery for the data center: a holistic approach

Data center migration relies heavily upon the ability to detect critical IT components in the original environment. Not all components are easy to detect using traditional discovery tools. For instance, load balancers are designed to be transparent to network traffic, making them invisible to normal scans. Also, the discovery task must be minimally invasive, since the IT environment to be migrated is usually in a production state until the relocation is complete. Studying the configuration of discovered host machines can reveal the presence of the network appliances they use, allowing a "short list" of probable appliance locations to be made, even if such appliances do not themselves respond to traditional network scans. This paper describes a collection of heuristics for detecting the presence of network devices in data centers, with a specific focus on detecting load balancers. Our approach lies in exploiting (1) host-based network data, which is often collected during data center migrations, and (2) knowledge of how load balancer appliances and managed servers are conventionally configured in an enterprise network. The effectiveness of our techniques is evaluated using data from an IBM data center migration project.