On our 6509 we have two WAN ethernet connections that I have setup using two default route statements to load balance, by destination not by packet, across both connections. This is working OK however I need to configure these routes so that there is failover should a single route goes down. Can I use Object Tracking in this scenario so that both routes continue to have an equal weighting but should the last resort route fail, traffic will failover to the other default route. In all of the documentation that I have read the on this subject mentions that failover to backup routes which isn't quite my situation.
All thoughts gratefully received
Why not? The point is that a route is injected or dropped from routing table depending on a track state. You'll assign the same administrative distance to both. Two ip sla's, two tracks.