Cisco IOS Path Control: PBR, IP SLA, and Offset Lists
Working reference for Cisco IOS path-control. Policy-Based Routing (PBR) with route-maps and ACLs to override the routing table for specific traffic on inbound interfaces, locally-originated PBR via ip local policy. IP SLA active measurement with icmp-echo / tcp-connect / http probes plus the schedule command. Track objects bound to IP SLA reachability or interface line-protocol, with delay debouncing to prevent flapping. Tying a static route to a track for automatic dual-WAN failover. Offset lists to add/subtract from routing protocol metrics. The combined PBR + IP SLA + floating static pattern for resilient dual-WAN. Pitfalls: PBR applied outbound, missing fallthrough, IP SLA without schedule, track delay too short, set ip next-hop without verify-availability.