Ok Here it is, this is how we tackled the OSPF Aggregation problem. To properly aggregate addresses within an internal type OSPF advertisement you must use the Area x range statement, this would not work because of the multi area setup and non-contiguous addresses. Stabilization of area 0 was a must because of the service provider environment, as well Link state changes would be constant due to customer networks. This would prevent us from using standard type areas due to routing table size and link state flapping. We needed to reduce the size of area 0 with summarization on the ABR's and keep all routes local to the areas to reduce the overall size of the routing table. We used NSSA areas because of one major feature "type 7 LSA's". What this allowed us to do is convert all routes to external type routes and aggregate the mutli areas on the ABR's. External type routes can be summarized using a summary statement with the summary being non area specific. To do this within an NSSA area you simply add the statement redistribute connected with some sort of filter like a prefix list and route map combination to prevent un-wanted routes, If you have any static routes you redistribute the static routes with the redistribute static statement with the same sort of filter control. This will convert all the area routes to type 7 LSA's (which are external) and allow you to summarize the routes with the summary-address command.
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