Two ISPs both advertise 8.8.8.0/24. The fast ISP (r2) was mis-set to LocPref 50, so the slow ISP (r3, default 100) always wins. Raise r2 to LocPref 200 and best-path flips — then a link drops and only one path remains. Open r1 to see the BGP table and the per-prefix Best-Path Decision. Try it hands-on: Q21 on RouteCrushLab.