My network currently exists as a single OSPF area, spread between 3 datacenters across the country. This has worked well for us because we don't have very complex routing issues and we've had the same three sites for years. We are now in a position though, where we are thinking about opening datacenters in other locations, including foreign datacenters.
My question is about single area vs. multi-area OSPF design. I don't have a lot of routers... and will probably never have any huge number. The links between the sites are all DS3's or higher, and in some cases redundant links are installed.
Would it make sense to move to a multi area OSPF design, with each site being it's own area, or would that be overkill? I've attached two diagrams indicating what I have setup now, versus what I imagine the multi-area design to be.
I see the following as potential benefits to a multi-area setup:
-route summarization between areas simplifies routing tables
-Less routes means less LSA's between geographically seperated sites
-Loss of Area 0 WAN link doesn't cause routing reconvergence problems at each site.
Drawbacks would include:
Any thoughts would be appreciated.