We have setup a dual-homed ISP setup using BGP. My topology is such that I have 2 routers that are handling the BGP- one for each provider. My preferred path is to use my .1 router, and fail over to my secondary .2 router. We have other ISPs as a second tier backup.
I've configured my .1 router with a route metric of 20 and my .2 router with a metric of 25. In my testing, when I unplug the ISP side of my router the NG continues to try and send traffic to my .1 and nothing goes to .2. I presume this is because the NG can still see my .1.
I'm thinking I should monitor the ISP side of my router to see if it's up. If it doesn't respond, then let the .2 handle the traffic.
Or if there is a better way, please let me know.