BGP session state, missing routes, prefix policy, default-originate, next-hop-self, route reflector — decision trees and checklists
SLA path failure workflow — read sla_paths.json, traceroute-first localization, ECMP handling, protocol triage
OSPF adjacency, LSDB, area types, authentication, route filtering, and redistribution — symptom-first decision trees with lookup tables
Cross-protocol redistribution (OSPF↔EIGRP) — seed metrics, subnets keyword, loop risk, route-map filtering
Path selection investigation — PBR, route-map and prefix-list policy influence, ECMP behavior, routing table verification