You are hired to design a solution that will improve network availability for users on a campus network with routed access. If the budget limits you to three components, which three components would y

Redundant power supplies in access routers eliminate a common single point of failure at the layer where users connect, providing hardware-level resilience without requiring a full device replacement.

Core routers in a well-designed campus are typically already dual-homed and carry aggregate traffic; investing an SSO budget component at the core provides less per-user availability improvement than protecting the access layer.

Distribution routers aggregate access traffic but are not the direct connection point for users; SSO at the distribution layer is less impactful than SSO at the access layer where individual user sessions terminate in a routed access design.

In a routed access design, access routers handle all first-hop routing for end users; adding standby route processors with SSO ensures that a processor failure causes a stateful switchover with no routing disruption rather than a full device reload.

Replacing copper links with fiber eliminates susceptibility to electromagnetic interference and crosstalk, reducing the likelihood of physical layer link failures and improving overall link reliability between campus devices.