This is driving me crazy and I cannot seem to figure it out.
Scenario:
DMVPN using cable internet as primary and LTE as backup at spoke
The cable internet seems to be garbage and causes BGP to flap, this in turn causes the spoke to bounce between primary and backup circuits essentially taking the site down
At first I thought BFD but that is too simple and will give me the same issue up down up down up down
Here's what I thought I could do, please tell me if I'm on crack...
Use IP SLA to track latency from spoke to hub tunnel IPs. If ICMP echos are not received or latency is too high, shut down that BGP session and fail over to LTE backup. The IP SLA will continue to monitor with ICMP echo between spoke and hub and once the internet connection stabilizes, for five minutes, revert back over to the primary cable circuit.
Here's the next part though, I'm thinking that if our primary circuit is flapping, eventually it will fail over to backup LTE and get the route to the primary circuit tunnels hub interface and then will bring back up the primary circuits BGP neighborship with the hub, so maybe what I'm trying to do won't work. Sorry, talking this out as I'm typing... hah
I'm able to create the SLA and see the ICMP packets but I'm not sure where to apply tracking nor how to tell the router that only bring BGP back up if pings are 100% success and latency is below 200ms for five minutes.
Is this even possible? If I can pull data from the other side of the world in under 2 seconds, I find it hard to believe that this technology is not available. :D
I'm at a loss. :(
Help!
