Describe redundancy and high availability in networks and name at least two standard methods or devices used to achieve it.

• A. Redundancy doubles bandwidth by adding more cables.
• B. Redundancy provides alternate paths and devices; high availability aims for minimal downtime; common methods include HSRP and VRRP for router failover; STP and link aggregation also help.
• C. High availability means servers are always on the same hardware.
• D. Redundancy only applies to storage.

Answer: (B)

Redundancy in networks means having duplicate components and paths so that if one element fails, another can take over without breaking connectivity. High availability is the result of designing networks to minimize downtime, ensuring services stay reachable even when faults occur.

Two standard ways to achieve this start with router failover capabilities. HSRP and VRRP let multiple routers share a single virtual gateway address, with one active router handling traffic and others ready to assume that role immediately if the active router fails. This keeps end users connected without having to reconfigure their settings.

On the switching and link layer, Spanning Tree Protocol prevents loops and provides alternative paths, so the network can reconfigure itself to keep traffic flowing if a link or switch fails. Link aggregation (sometimes called EtherChannel or LACP) combines several physical links into one logical link, increasing capacity and providing automatic failover if any individual link drops.

This combination—alternate paths and devices, fast failover, and shared gateway or bandwidth mechanisms—embodies redundancy and the goal of high availability. Other options either oversimplify redundancy, misstate what high availability means, or incorrectly limit where redundancy applies.