OSPF Summarization

RouterOS General
1

Hello,

I’ve got the following setup: 2 x CRS317 and 1 PFSense router. The PFSense is set to export all the connected and static routes into area 5. The CRS317 connected to the PFSense is a part of Area 0 and Area 5, while the other CRS317 is just a part of the Area 0.
The PFSense exports some subnets, for example the public subnet (/27), and then a lot of /32s inside that public subnet, which are defined as alias IPs. How can I set the CRS317 that’s directly connected to the PFSense to summarize this subnet into a single /27 and stop the forwarding of /32 IPs - since those don’t really do anything (if I already have the /27 subnet advertised, sending a ton of /32s won’t really help).

I already tried the Area Range, but it doesn’t seem to do anything (obviously I’m missing something) and I would really love if this could be done automatically.

P.S. newbie when it comes to OSPF so I’m probably missing some information about how this can be achieved…

Thank you.

2

https://help.mikrotik.com/docs/display/ROS/OSPF#OSPF-RouteSummarisation

3

Thank you.

I am failing to understand why the routes coming from the PFSense are considered external:

Inter-area route summarization works on area boundaries (ABRs), it does not apply to external routes injected into OSPF via redistribution

The PFSense indeed redistributes the connected routes. This means that they get injected into the router connected to it as external???

I guess I should go for the 2nd solution, using routing filters, but I was looking for a checkbox or something saying “Summarize routes coming from this neighbor” or something :frowning: