You want traffic to fail over to ISP-B automatically if ISP-A becomes unreachable, using IP SLA. Which configuration pattern is required?

This configuration pattern is the standard and most reliable method for automatic failover using IP SLA. An IP SLA probe actively monitors the reachability of ISP-A. A track object then links the state of this probe to the primary static default route. If the IP SLA probe fails, the track object changes state, causing the primary static route to be removed from the routing table. The floating static route, which has a higher administrative distance (making it less preferred under normal circumstances), then becomes the active default route, directing traffic to ISP-B. Incorrect options: A distributed ACL blocks traffic but doesn't dynamically change routing paths based on ISP availability. PBR without tracking would require manual intervention or another mechanism to detect ISP-A failure. Decreasing the administrative distance of ISP-B's route would make it preferred over ISP-A's route, preventing failover to ISP-A as the primary.