Community discussions

MUM Europe 2020
Topic Author
Posts: 48
Joined: Tue May 10, 2011 6:11 am

PPPoE and OSPF Questions

Tue Jun 28, 2011 8:22 pm


I have a question regarding PPPoE subnets for clients. My configuration is as follows:

I have one OSPF area for the /30 between another Cisco router and the MT 450G (200). According to documentation that I found on these forums, in order to keep PPPoE /32's from flooding my routing table every time a client connects/disconnects (forcing the MT to announce an aggregate/summarized route for all of the PPPoE IP's rather than just /32's), I need to put the PPPoE subnet into a separate OSPF area on the MT. This seems to work, instead of seeing /32's in my routing table, I now see the aggregate /25. So far, so good. Note, I am not using the "backbone" (area 0) area on my MT.

Ever since this configuration has been applied, randomly, the MT will stop redistributing it's connected routes into OSPF. The OSPF neighbor session between my Cisco and MT remains alive, and no errors are logged, but the MT just stops redistributing. When things are working properly, on the MT, under "AS Border Routers," the Cisco neighbor appears. When the problem occurs, the Cisco neighbor disappears from this list (all that remains is the MT its self). The only way to get the MT to start redistributing it's connected routes into OSPF again is to disable the OSPF instance and re-enable it.

I am running RouterOS 5.2. I can't see anything on the logs of either the Cisco or the MT (debug is enabled). Is it possible that I have hit a bug? Do I really HAVE to put my PPPoE subnet into another area in order to announce an aggregate?



Who is online

Users browsing this forum: aix150, noexp and 74 guests