We have two facilities connected via dark fiber, internet out both to the same ISP. Matching hardware at both sites, ASA ad ISR. Currently they are configured to use HSRP, one being primary at all times, the other just standing by in case we lose the internet link, or some other failure. They are talking to each other via iBGP, so dual default routes in the table for fast switchover. On paper, looks like a good layout, however, we have been going over scenarios of possible failures and discovered an issue.
The router and firewall at the primary location is connected to a switch, which is then uplinked to the core, the other building is directly connected. At some point the primary will be connected directly to the core as well, but that still leaves us with an issue. If the primary loses the core switch, it will lose iBGP, and HSRP communications to the other building. All traffic will then route to the other building through the secondary switch, but the primary router will still be connected to the internet, and so will the firewall. At this point both routers and firewalls will think they are active.
I need a better solution to this so that if primary loses internal connectivity, all routing will failover to the secondary and not advertise through primary. Do we need to use HSRP for this, or setup all public facing routers and firewalls to use BGP?
The locations are mirrored, identical gear at both sites, except for the WAN switch in the middle at primary site, which is going away at some point. There are a few routers behind the internet router for DMVPN, along with an ASA, soon to be 2 ASA. They all use static routes to point to the VIP of the Internet HSRP. How can I set this up to also load balance across both links? If I load balance, would that also resolve the failover issue?
