MK1
[admin@MK1] > /ip address print
Flags: X - disabled, I - invalid, D - dynamic
# ADDRESS NETWORK INTERFACE
0 10.10.10.1/30 10.10.10.0 ether1

[admin@MK1] > /interface export
# nov/19/2015 14:58:55 by RouterOS 6.32
# software id =
#
/interface bridge
add name=null


[admin@MK1] > /ip route print
Flags: X - disabled, A - active, D - dynamic,
C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme,
B - blackhole, U - unreachable, P - prohibit
# DST-ADDRESS PREF-SRC GATEWAY DISTANCE
0 ADC 10.10.10.0/30 10.10.10.1 ether1 0
1 A S 192.168.0.0/20 null 1
2 A S 192.168.0.0/24 null 1
3 A S 192.168.1.0/24 null 1
4 A S 192.168.2.0/24 null 1
5 A S 192.168.3.0/24 null 1
6 A S 192.168.4.0/24 null 1

[admin@MK1] > /routing ospf export
# nov/19/2015 14:56:34 by RouterOS 6.32
# software id =
#
/routing ospf instance
set [ find default=yes ] redistribute-static=as-type-1
/routing ospf network
add area=backbone network=10.10.10.0/30


MK2
[admin@MK2] > /ip address print
Flags: X - disabled, I - invalid, D - dynamic
# ADDRESS NETWORK INTERFACE
0 10.10.10.2/30 10.10.10.0 ether1

[admin@MK2] > /routing ospf export
# nov/19/2015 14:57:59 by RouterOS 6.32
# software id =
#
/routing ospf instance
set [ find default=yes ] redistribute-static=as-type-1
/routing ospf network
add area=backbone network=10.10.10.0/30

[admin@MK2] > /ip route print
Flags: X - disabled, A - active, D - dynamic,
C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme,
B - blackhole, U - unreachable, P - prohibit
# DST-ADDRESS PREF-SRC GATEWAY DISTANCE
0 ADC 10.10.10.0/30 10.10.10.2 ether1 0
1 ADo 192.168.0.0/20 10.10.10.1 110
2 ADo 192.168.1.0/24 10.10.10.1 110
3 ADo 192.168.2.0/24 10.10.10.1 110
4 ADo 192.168.3.0/24 10.10.10.1 110
5 ADo 192.168.4.0/24 10.10.10.1 110



Where is the 192.168.0.0/24 network on router MK2?

I would say included in 192.168.0.0/20...
Probably a bug.

I would not put this as a bug right away.
192.168.0.0/24 IS icluded in 192.168.0.0/20
Although 192.168.1.0/24 up to 192.168.4.0/24 are also included.

More basic question, why do you have these overlapping subnets in the first place?

We could have a third router MK3 that also send the 192.168.0.0/24 network causing the traffic flow to MK3 what should flow to MK1 router due of the ospf cost.

We could have a third router MK3 that also send the 192.168.0.0/24 network causing the traffic flow to MK3 what should flow to MK1 router due of the ospf cost.

This is quite a valid reason. I would report it as a bug.

It also happens if the supernet and subnet are both redistributed, but from different sources.
(I only tested with connected and static as the sources, but I'm sure BGP and other sources would do the same)

I noticed that this "aggregation" does not happen if the /24 route is an actual ospf interface (as opposed to a redistributed route) while the supernet is a redistributed route.

Mikrotik support:

"Hello,

Thank you for the report. It appears that OSPF is not sending LSAs for the same ID
but different netmasks."

"Hello,

It seems that there are no easy fix for this problem. Major changes in code is
required. You will have to wait for RouterOS v7 release, where this problem is
addressed."

Mikrotik support:

"Hello,

Thank you for the report. It appears that OSPF is not sending LSAs for the same ID
but different netmasks."

"Hello,

It seems that there are no easy fix for this problem. Major changes in code is
required. You will have to wait for RouterOS v7 release, where this problem is
addressed."

Mikrotik developers remember this bug please. It's very annoying.

As it is mentioned in support mail bug is addressed in ROS v7. We cannot fix it without rewriting base of OSPF.