An engineer is trying to configure a Page Load test and is trying to assign...

In the framework ofDesigning and Implementing Enterprise Network Assurance (300-445 ENNA), selecting the appropriate agent for specific test types is a critical configuration step. The ThousandEyes platform utilizes different agent binaries and capabilities depending on the underlying hardware and software environment. Specifically,Page Load testsandTransaction testsrequire the agent to have a browser engine (Chromium) installed and functional to render web content and measure DOM-related metrics.

According to the ENNA implementation guidelines, not all Enterprise Agents support these browser-based tests. The exhibit displays a "New Test" configuration screen where the engineer is searching for "east1-agent-1". While other agents like "west-2-ag-1" are visible, the designated agent is missing because itdoes not support Page load tests(Option D). This common occurrence happens when an Enterprise Agent is deployed on resource-constrained hardware—such as certainCisco Catalyst 9000 switchesorCisco ISR 4000 series routers—where the Chromium browser package is either not supported or has not been enabled due to memory and CPU limitations.

When an agent lacks the required capabilities for a specific test layer (e.g., Web layer tests), it is automatically filtered out from the selection list in the ThousandEyes portal to prevent invalid test configurations. To identify compatible agents, an engineer can look for the "Browser" or "Dual Chromium" labels in the agent settings. If the "east1-agent-1" were merely offline (Option A), disabled (Option B), or still registering (Option C), it would typically still appear in the list but with a status indicator showing its unavailability, rather than being entirely hidden from the test assignment menu. Therefore, the absence of the agent in a web-layer test configuration explicitly indicates a lack of functional support for the required browser-based metrics.