Routing Filters and OSPF

Hello,

I have not been able to find any posts with a similar problem as mine so I apologize if I overlooked any.

I have recently taken up a job as network administrator in a network of almost all Mikrotik ( yay! )
We are running ospf throughout our network and using natted privates for customer IP’s, and what I would like to do is filter out the private ip blocks from the OSPF routing tables. This seemed easy enough but for some reason on the first router I tried this on I am still seeing 10.x.x.x ip blocks from an adjacent router. I have gone into the routing> filters section and used 10.0.0.0/8 as prefix and ospf-in and ospf-out for the chains in my first and second filter rules. I have set action to “discard”. Am I wrong in expecting 10.0.0.0/8 to filter out the entire 10. block? Or must I actually use the block size in individual filters such as 10.0.0.1/24, 10.0.0.2/24 etc? Thanks in advance!

Chad…

Only external routes can be filtered. Filtering other routes would break OSPF.