My customers have one central site and n remote site. Each one with a link MPLS. The customers buy another link (internet /ppp) and want to use this link like backup preemptive, using this link with VPN (site-to-site).
My doubt is, using HSRP in the central site, when the link (MPLS) of remote site down, the remote forward date by internet/vpn, but like the central site would response to this remote site? The active router is up, but the link destination is down!