It is OSPF Design query on OSPF filtering using DISTRIBUTION-LIST.
I know that DISTRIBUTION-LIST prevents prefix to get into the routing table but donot prevent the LSA or modify the topology table.
Thus, for example if I use DISTRIBUTION-LIST to prevent a prefix 192.168.1.1 in routing table of a RouterA which is in Area 0 and but the same prefix 192.168.1.1 is present in the routing table of RouterB which is in Area1. If RouterB wants to reach 192.168.1.1 the packet is reaching RouterA which is suppose to be the path to reach 192.168.1.1, and blackholed as this prefix is not available in the RIB.
Thus, two thing i want to know here
1. Does the summary LSA generated by ABR checks its routing table before generating summary LSA? I think summary LSA generated by ABR is not depanding on the ABR routing table (Thus because, the blackhole is created in our case). Is this correct?
2. What is the advantage or real time usage of DISTRIBUTION-LIST as it creates inconsistent topology as in our case?
Thanks for your patience reading this bit lengthy explanation
Waiting for your valuable reply