My boss wants to do something that I don't think is possible. I'd like some ammunition in saying so. We currently have a Cisco 5510 firewall with two outbound Ethernet links. One of these links goes to a private network, and the other to the public Internet. The way that traffic is currently configured, all Internet traffic is routed through the private network to the data center, using the outbound link there. The public link on the 5510 is in place just in case that private network link fails, so we can preserve at least some connectivity.
My boss feels this link is being wasted. He wants a solution that allows that link to be married to the other Ethernet link into the private network. (Within the private network, we have 2821s with two serial links combined into a multilink PTP connection. I think that's where he got the idea.) Then, and this is the kicker, if and when the device at the far end of that link fails, he wants the two Ethernet connections to recognize that, and automatically switch to start routing traffic across the Internet. With no engineer intervention.
I think he understands that this won't work with a firewall, but he's wondering if there's any hardware we could add to facilitate this. I'm sure there's hardware that can handle this, but that assumes that it's even possible in the first place. And I honestly can't picture how you would set this up with a private network and the Internet.
Any help at all is appreciated. I've been chasing a triple-CCIE for a few weeks now, and my boss is running out of patience.