I have an OSPF area for which I wish to select which external routes enter it. This area has default routes comming from two points, so I cannot make it a stub area as to do so makes the default route injection unconditional, which I don't want.
So I can use distribute-lists to control externals on the ASBR sourcing the routes, I can use area prefix lists to filter type 3 LSAs on the ABR. I can use distribute lists on any OSPF router to prevent it from using the LSA type 5 when it receives it, but not flooding it on. I can even filter entries from the area database, a potentially very dodgy thing to do.
But I can't find any way to filter type 5s, which is essentially distance vector information, like type 3's are.
Can someone point out what I'm missing please, as this cannot actually be the case, its simply too stupid, so it must be me.