First Hop Redundancy

having a single gate to your gated neighborhood is bad because what if they just lock you in one day

In a full or partial mesh network topology, alternate routes can be found to bypass failed routers or faulty connections. However, end systems are typically configured with a single router that acts as their default gateway. While it's technically possible to configure hosts with multiple default gateways, it's not feasible in practice.

This is why we have First Hop Redundancy Protocols. To learn more, view the page on FHRPs.