In cisco speak, with pretty pictures: http://www.cisco.com/en/US/tech/tk583/tk372/technologies_configuration_example09186a00800a43f6.shtml
On OpenBSD, it works analoguously, except that it's much cleaner :) Just think of the ipsec secured gre tunnel as a wire from point A to B. Make two such wires. Then run a routing protocol on them to redundantly route your traffic through. Some things to consider: 1. What if the internet links fail some other way than completely dead, like high packet loss? 2. The rest of the system probably isn't as reliable as you think, if you can't have much money for making the internet links redundant. -- Jussi Peltola
