300-420 Practice Questions

Large EIGRP networks require careful hierarchy and query-boundary design. A structured hierarchical topology with route summarization is one of the most important scaling techniques because summarization reduces routing table size, hides topology changes, and limits the EIGRP query scope when failures occur. This improves convergence and reduces CPU and bandwidth consumption on routers that do not need detailed route visibility. Implementing multiple EIGRP autonomous systems can also be used as a scaling technique in very large designs because it creates administrative and query boundaries, although it introduces redistribution and policy complexity that must be controlled. Sub-second timers are not a primary scaling method; aggressive timers can increase control-plane load and do not reduce the size of the routing domain. Distribute lists can filter routes, but broad filtering alone is not the core scaling architecture for a network with more than 1000 routers. Modifying delay values influences metric calculation and path selection, not EIGRP domain scale. Therefore, the valid scaling techniques are structured hierarchy with summarization and, where justified, multiple EIGRP autonomous systems.

Dial-In: collector initiates a session to the device; supports gRPC only. Dial-Out: device initiates a session to the collector; supports TCP, UDP, and gRP

C.  

Model-driven telemetry can be deployed in dial-in or dial-out mode, and the difference is which side initiates the session and where the subscription is controlled. In dial-in mode, the collector initiates the session to the network device and requests the telemetry subscription. This makes the collector responsible for establishing the session and asking for the data stream. In the context of the provided options, dial-in is paired with support for gRPC only. In dial-out mode, the network device initiates the session toward the collector according to a configured subscription. This is useful when devices sit behind NAT or when the operational model requires devices to push telemetry to a known collector. In the provided choices, dial-out is paired with support for TCP, UDP, and gRP

C.