We have a requirement from our customer to have a fully redundant path to the outside internet. The servers within our enclave will need to be able be routed to by an external enclave. The switches with the network are setup as the primary and secondary default gateways for the internal network. How can we advertise the sole network we have and have each piece of equipment within the chain paying attention to failures ahead so that the route back can be poisoned and traffic be diverted to the secondary path? I don't have a issue if the solution brings in load sharing, unfortunately I can't solve a way for a windows computer to use a secondary default gateway if the first is still working. Thanks for your help.
You could try HSRP on the inside interface of both routers. As long as both
inside interfaces are on the same subnet, the HSRP can make sure that the
default gateway IP is always held by an active device.
With regard to advertising the 200.x.x.x subnet is concerned, you can
configure conditional route advertisement (if using BGP).
Hope this helps.