I am looking to implement OSPF to manage dynamic routing in our internal environment, however, also include dynamic routing to other company networks and locaitions.
Currently all internal routing is handled via static routes between our core and firewalls.
We are in the process of building new infrastructure to run in parralel with what's in place.
The new infrastructure comprises of two 6509-e swtiches which will be the core/distribution and another two 6509-e switches to handle the access layer. We will also be using a pair of asa 5500 firewalls with connections to the internet and 3rd party vendors. We will be using a totally new IP scheme on this new infrastructure.
I will also need to have dynamic routing to 9 additional sites spread accross the region with various links either layer 2 or vpn tunnel etc..
I would like the core 6509 to be the OSPF backbone of the network but don't know if I should have the other locations be a part of Area 0 or should I have every other physical location be in their own area? Some of the other locations are poorly managed and there is a good chance that non-scheduled events will occur during productions hours that could trigger route convergence. What can I do from a design/implementation standpoint to protect this new main core infrastructure from major route convergence? For example, I don't want a power outage in one of our smaller locations to effect or cause disruption to all routing in the network. But at the same time I still need redundancy to any failed link/hardware to take place in a resonable amount of time. How or what kind of precautions can I make before hand to prevent such repercussions as well as maintain proper routing convergence throughout?