OSPF and IS-IS both scale link-state routing by limiting how far topology information must be flooded and recalculated. OSPF uses areas; IS-IS uses Level 1 […]

Resilient enterprise BGP design is about preserving policy and reachability when links, providers, route reflectors, or sites fail. BGP already has mechanisms for selecting alternate […]

Campus high availability is a system design problem that spans physical redundancy, Layer 2 loop prevention, first-hop gateway resilience, routed convergence, power, software, and operational […]

Cisco Software-Defined Access changes campus design by separating endpoint identity and segmentation from the physical underlay that transports packets. A fabric site combines edge nodes, […]

Quality of Service and multicast are often taught as separate feature sets, but enterprise design frequently brings them together. Multicast determines how one source efficiently […]

Designing an enterprise network is the practice of choosing a topology and its control planes under constraints, not selecting the most feature-rich protocol for every […]