At each of our sites we have dual MPLS providers, each connected to their own dedicated CE routers. We are running eBGP with each provider's PE, and iBGP between our two CE routers. All works well under normal circumstances. If a single provider's circuit goes down and the BGP neighbor is lost, traffic is automatically re-routed via the other CE and provider. However, often times we encounter a situation whereby issues deep within the provider MPLS cloud (such as routing issues or failed links) do not materalize on our CE routers - no circuit outages or BGP neighbor loss. Thus traffic continues to be routed via the troubled provider and is black holed deep within their network. The only solution for this is to manually shutdown the eBGP neighbor on the CE connected to the troubled provider so that traffic takes the alternate path learned via iBGP to the other provider.
Are there any mechanisms we could configure on our CE routers to monitor remote sites to make sure that the forwarding path is indeed intact despite what the PE eBGP peer tells us ? If a forwarding path is then determined to be invalid, could a configuration change be initiated to shutdown the peer so traffic would be re-routed through the other provider ?
