I am building two data centers, each with internet connectivity from two service providors. One data center will be primary, with the other used for DR. I plan to inject a default route into my core by tunneling BGP through my firewalls directly to the core. Now, I can easily direct all internet traffic to the primary DC by setting local preference higher on the default routes recieved from the primary providors. However, if I wanted the ability to route traffic out both data centers at the same time, things get more complicated because BGP will only select the one best route to enter into the routing table. What is the best way route Internet traffic to both data centers at the same time?
