OSPF Duplicating Routes

RouterOS Forwarding Protocols
1

We have a weird issue when we enable a second core router, we will get multiple copies of routes, some pointing at routers that dont originate those routes. This is causing our routing to stop as we get packets bouncing back and forth between routers. Some of the duplicated routes are networks that are directly configured on that router. Has anyone else seen this issue?

R1 and R2 are both connected to the internet at separate datacenters
R3 and R4 are located in a third datacenter
R5 is actually around 80 other routers
10G fiber connected between all routers
OSPF and OSPFv3 configured on all fiber circuits and loopbacks
OSPF and OSPFv3 are setup as PTP connections
Running v7.6

2

Disabling OSPF will keep the routes in the table, they are just marked invalid. It really seems like the table is not updating or removing entries correctly. Tried firmware v7.7RC2 with no improvements

[admin@Core2new] > /ip/route/print terse where dst-address=10.20.7.0/24
DAo+ dst-address=10.20.7.0/24 routing-table=main gateway=100.76.0.73%qsfp28-2-1 immediate-gw=100.76.0.73%qsfp28-2-1 distance=110 scope=20 target-scope=10 suppress-hw-offload=no
DAo+ dst-address=10.20.7.0/24 routing-table=main gateway=100.77.0.69%vlan901 immediate-gw=100.77.0.69%vlan901 distance=110 scope=20 target-scope=10 suppress-hw-offload=no
DAo+ dst-address=10.20.7.0/24 routing-table=main gateway=100.77.0.69%vlan901 immediate-gw=100.77.0.69%vlan901 distance=110 scope=20 target-scope=10 suppress-hw-offload=no
DAo+ dst-address=10.20.7.0/24 routing-table=main gateway=100.76.0.73%qsfp28-2-1 immediate-gw=100.76.0.73%qsfp28-2-1 distance=110 scope=20 target-scope=10 suppress-hw-offload=no
3

We have the same problem with v7.13.1 (last version). How have you fixed it?

4

have u tried on v6?

5

I have a similar topology, to include multiple sites running on 7.13.2. I am not able to replicate this behavior with OSPF PtP configurations. Have you taken a look at what is being redistributed into OSPF? It would seem as though perhaps there is a router in your mix which may be redistributing OSPF. Generally I have had success with just connected and static routes if your topology allows for that.

6

Unfortunately, just restarting will solve the problem.
There is some bug in v7 that is duplicating sessions.
This needs to be investigated by Mikrotik.
I’m using 7.14.3