In MikroTik RouterOS version 7, route filtering (OSPF filters) works by default with a "closed" policy, similar to a firewall filter, where everything that is not allowed is blocked. This differs from the behavior in version 6, where nothing was blocked by default.
Examples:
/routing filter rule
add chain=ospf-in disabled=no rule="if (dst in 192.168.0.0/16 && dst-len in 16-32) {accept;}"
add chain=ospf-in disabled=no rule="if (dst in 10.0.0.0/8 && dst-len in 8-32) {accept;}"
The inconsistency is when delivering OSFP DFoI routes.
I have this case study I have 3 Router A / B / C.
Router A is the router that gives out has 2 areas, one OSFP area against edge router by transport.
The other area with Router B and C as mentioned above, both areas only do OSFP PTP, one area only against the edge and one area for Router B and C.
Even though Router A are well-executed filters rejecting all outbound routes to Router B and C, nothing is being selected to redistribute; likewise, Router B and Router C know their routes via OSFP instance 110 by DFoI.
Apart from that, I am rejecting the incoming routes in Router B and C, in Router B and C if I only redistribute connected and static.
I summarize the routes on Router B and C with blackhole.
No matter how PTMP, PTMP Broadcast, PTP are configured, the only way is to do another area, either Router B or C, so as not to see these DFoI routes, but it doesn’t make sense because in the structure there are no disadvantages that belong to the same area.
In a simple and concise sense, Router A receives, knows all the routes, Router B and C do not have or should know any routes only have routes by default it does not need to have more.
But Router B and Router C are also known as DFoI, I know they’re inactive routes but I don’t want those routes in those tables.
This is not "Site Feedback"
Please always use English, so please correct the topic title.
Sorry, I'm new to the forum, I just wanted to comment on this case study to see if anyone else had experienced it.