In which phase is the horizontal probe fired during Infrastructure Discovery Patterns?

The horizontal probe is fired during the Identification phase of Infrastructure Discovery Patterns because this is when the system starts to identify and gather information about the devices and resources in the network. Specifically, the horizontal probe is used to collect data about systems that are within the same network segment, allowing for the discovery of devices that are connected to routers or switches.

At this stage, the approach is to map out the network by identifying available devices, understanding their configurations, and correlating their presence with existing data in the configuration management database (CMDB). This crucial activity sets the groundwork for establishing a comprehensive view of the infrastructure, which can be built upon in subsequent phases.

In the earlier phases, such as Preparation, the focus is primarily on setting up the necessary configurations and requirements for the discovery process. The Testing phase usually involves verifying if the discovery patterns work correctly before full-scale implementation, while the Implementation phase is focused on deploying these patterns and ensuring an ongoing discovery process. Thus, the Identification phase is specifically designated for firing the horizontal probe.