OSPF with unnumbered interfaces with multiple areas possible?


I'm following this article https://support.cumulusnetworks.com/hc/en-us/articles/202796476-OSPF-Unnumbered-Sample-Configuration... to setup OSPF with unnumbered interfaces on my CumulusVX test environment.
I've successfully connected two routers in area 0.0.0.0.
I tried to add another router in a different area 0.0.0.1, but it doesn't show up as a neighbor.

Each router has a /32 on lo and all its interfaces.

Is it even possible to use multiple areas with unnumbered interfaces?
If yes, what might be wrong?

Router "core1" is connected (swp1, swp2) to "core2" (swp1, swp2).
Router "aggr1" is connected (swp1, swp2) to "core1" (swp3, swp4)

config from core1:

interface swp1
ip ospf network point-to-point
!
interface swp2
ip ospf network point-to-point
!
interface swp3
ip ospf network point-to-point
!
interface swp4
ip ospf network point-to-point
!
router-id 10.0.0.0
!
router ospf
ospf router-id 10.0.0.0
network 10.0.0.0/32 area 0.0.0.0
network 10.0.0.2/32 area 0.0.0.1


Config from aggr1:

interface swp1
ip ospf network point-to-point
!
interface swp2
ip ospf network point-to-point
!
router-id 10.0.0.2
!
router ospf
ospf router-id 10.0.0.2
network 10.0.0.0/32 area 0.0.0.0
network 10.0.0.2/32 area 0.0.0.1

5 replies

Userlevel 4
Recommend doing the area config under the interface... when interfaces are cloning IP addresses everywhere as they do for unnumbered configs using the "ip ospf area 0.0.0.1"

A similar config would be recommended for aggr1

On core1:
interface swp1
ip ospf network point-to-point ip ospf area 0.0.0.0
!
interface swp2
ip ospf network point-to-point ip ospf area 0.0.0.0 ! interface swp3 ip ospf network point-to-point ip ospf area 0.0.0.1 ! interface swp4 ip ospf network point-to-point ip ospf area 0.0.0.1
Thank you!
Works fine.
I've still got one question:

Do you know why all routers are in state "Full/DROther"?
There are no routers in backup state.

When running OSPF with numbered interfaces, I see the expected scheme: one is "Full/DR" and others are "Full/Backup".

Stupid me.
It's because I configured point-to-point and with this network type there's no DR/Backup election needed.
Userlevel 4
Rainbow Dash wrote:

Stupid me.
It's because I configured point-to-point and with this network type there's no DR/Back...

You've got it.

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