Trying to understand OSPF Point-to-Multipoint Non-Broadcast

Hi,

Im hoping that someone can explain to me the way OSPF works on a
Point-to-Multipoint Non-Broadcast.

Let me explain the situation Im running across. I need to connect three
routers using OSPF. The routers are:

R1 fa0/0 (10.1.1.1/24) _-` fa0/0 (10.1.1.2/24) R2 fa0/1 (10.2.2.1/24) _ `
fa0/1 (10.2.2.2/24)R3

R1

Interface fa0/0

Ip add 10.1.1.1 255.255.255.0

Router ospf 1

Network 10.1.1.1 0.0.0.0 area 0

R2

Interface fa 0/0

Ip address 10.1.1.2 255.255.255.0

Interface fa 0/1

Ip address 10.2.2.1 255.255.255.0

Ip ospf network point-to-multipoint non-broadcast

Router ospf 1

Network 10.1.1.2 0.0.0.0 area 0

Network 10.2.2.1 0.0.0.0 area 1

Neighbor 10.2.2.2

R3

Inter fa 0/1

Ip address 10.2.2.2 255.255.255.0

Ip ospf network point-to-multipoint non-broadcast

Router ospf 1

Network 10.2.2.2 0.0.0.0 area 1

Neighbor 10.2.2.1

All connections are Ethernet. The restrictions given are that R2 to R3
cannot form a DR/BDR relationship and they are not allowed to exchange
multicast.

My configuration is to use Point-to-Multipoint Non-Broadcast on the R2 to R3
interfaces. When I do that I get a surprising result.

I get 2 routes on R1 that are both /32 for 10.2.2.1 and 10.2.2.2 Im also
not getting the /24 for the 10.2.2.0/24 that Im expecting.

R1 show ip route

O IA 10.2.2.2/32 [110/2] via 10.1.1.2, 00:00:34, FastEthernet0/0

C 10.1.1.0/24 is directly connected, FastEthernet0/0

O IA 10.2.2.1/32 [110/1] via 10.1.1.2, 00:01:07, FastEthernet0/0

Im trying to understand why the /32 are showing up. My guess would be that
the point-to-multipoint non-broadcast is causing the issue but Im just not
sure.

The second problem that Im trying to understand is why does the route for
10.2.2.0/24 not appear on R1.

Any insight would greatly appreciated.

Thanks,

Andy

Blogs and organic groups at http://www.ccie.net
Received on Sat Jun 04 2011 - 20:59:51 ART