We are deploying a new solution with our ISP. They are providing redundant links so our router has 2 interfaces connected to ISP-RTR1 and ISP-RTR2. They have provided us with a /25 range of addresses and the full setup should look like the attached drawing.
On our side we have one router going to two separate routers on the ISP's side. They only have one interface active at a time so it is up to us to select which interface we will use and how to switch it over in the event of a failure. The ISP's address is .1 and our router .2 and .3... I am thinking IPSLA is our best bet here but I am not all that familiar with it and wanted to get other's opinions on this.