OSPF Point-to-Multipoint config

While playing a little bit with an OSPF lab i had to configure Point-to-Multipoint network type,
Using the following Scenario:
(the post is related to R2, R5 and R6 only)

R2, R5 and R6 are all connected using frame-relay, dlci 205-502 connect R2 to R5 and dlci 206-602 connect R2 to R6.

R2 config:
interface Serial0/0
ip address 10.1.56.2 255.255.255.0
encapsulation frame-relay
ip ospf network point-to-multipoint non-broadcast
clock rate 2000000
frame-relay map ip 10.1.56.5 205 broadcast
frame-relay map ip 10.1.56.6 206 broadcast
frame-relay interface-dlci 205
frame-relay interface-dlci 206
no frame-relay inverse-arp
router ospf 1
router-id 2.2.2.2
log-adjacency-changes
network 10.1.56.2 0.0.0.0 area 1
network 10.1.123.2 0.0.0.0 area 0
neighbor 10.1.56.6
neighbor 10.1.56.5

R5 config:
interface Serial0/0
ip address 10.1.56.5 255.255.255.0
encapsulation frame-relay
clock rate 2000000
frame-relay map ip 10.1.56.2 502 broadcast
frame-relay interface-dlci 502
no frame-relay inverse-arp
router ospf 1
router-id 5.5.5.5
log-adjacency-changes
network 5.5.5.5 0.0.0.0 area 1
network 10.1.56.5 0.0.0.0 area 1
neighbor 10.1.56.2

R6 config:
interface Serial0/0
ip address 10.1.56.6 255.255.255.0
encapsulation frame-relay
clock rate 2000000
frame-relay map ip 10.1.56.2 602 broadcast
frame-relay interface-dlci 602
no frame-relay inverse-arp
router ospf 1
router-id 6.6.6.6
log-adjacency-changes
network 6.6.6.6 0.0.0.0 area 1
network 10.1.56.6 0.0.0.0 area 1
network 10.6.0.0 0.0.3.255 area 1
neighbor 10.1.56.2

As you may recall OSPF network type point-to-multipoint doesn't use DR/BDR election and due to the use of the neighbor statement, hello and updates, are exchange via unicast.
But still, although i have configured ospf network type point-to-multipoint on R2 s0/0 interface something is missing and because of that i do see adjacency's but no routing exchange has occur?!

R2#sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface
R1 1 FULL/DROTHER 00:00:39 10.1.123.1 FastEthernet0/0
R3 1 FULL/BDR 00:00:36 10.1.123.3 FastEthernet0/0
6.6.6.6 0 FULL/ - 00:01:46 10.1.56.6 Serial0/0
5.5.5.5 0 FULL/ - 00:01:33 10.1.56.5 Serial0/0

R2# sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

2.0.0.0/24 is subnetted, 1 subnets
C 2.2.2.0 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 6 subnets
O 10.1.3.0 [110/11] via 10.1.123.1, 00:44:09, FastEthernet0/0
O 10.1.2.0 [110/11] via 10.1.123.1, 00:44:09, FastEthernet0/0
O 10.1.1.0 [110/11] via 10.1.123.1, 00:44:09, FastEthernet0/0
O 10.1.0.0 [110/11] via 10.1.123.1, 00:44:09, FastEthernet0/0
C 10.1.56.0 is directly connected, Serial0/0
C 10.1.123.0 is directly connected, FastEthernet0/0

The reason for this behavior is because i didn't configure the network type on R5 and R6.

R5# sh ip ospf interface s0/0
Serial0/0 is up, line protocol is up
Internet Address 10.1.56.5/24, Area 1
Process ID 1, Router ID 5.5.5.5, Network Type NON_BROADCAST, Cost: 64
Transmit Delay is 1 sec, State DR, Priority 1
Designated Router (ID) 5.5.5.5, Interface address 10.1.56.5
Backup Designated router (ID) 2.2.2.2, Interface address 10.1.56.2
Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
oob-resync timeout 120
Hello due in 00:00:16
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 6
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 2.2.2.2 (Backup Designated Router)
Suppress hello for 0 neighbor(s)

R5 believe that the network is NON_BROADCAST which act differently (DR/BDR election) form PtMP network type.

Configuring the network type on interface s0/0 on R5 and R6 will fix the problem.

R2#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

2.0.0.0/24 is subnetted, 1 subnets
C 2.2.2.0 is directly connected, Loopback0
5.0.0.0/24 is subnetted, 1 subnets
O 5.5.5.0 [110/65] via 10.1.56.5, 00:00:01, Serial0/0
6.0.0.0/24 is subnetted, 1 subnets
O 6.6.6.0 [110/65] via 10.1.56.6, 00:00:01, Serial0/0
10.0.0.0/8 is variably subnetted, 12 subnets, 2 masks
O 10.1.3.0/24 [110/11] via 10.1.123.1, 00:51:08, FastEthernet0/0
O 10.1.2.0/24 [110/11] via 10.1.123.1, 00:51:08, FastEthernet0/0
O 10.1.1.0/24 [110/11] via 10.1.123.1, 00:51:08, FastEthernet0/0
O 10.1.0.0/24 [110/11] via 10.1.123.1, 00:51:08, FastEthernet0/0
O 10.6.0.0/24 [110/65] via 10.1.56.6, 00:00:01, Serial0/0
O 10.6.1.0/24 [110/65] via 10.1.56.6, 00:00:01, Serial0/0
O 10.6.2.0/24 [110/65] via 10.1.56.6, 00:00:01, Serial0/0
O 10.6.3.0/24 [110/65] via 10.1.56.6, 00:00:01, Serial0/0
C 10.1.56.0/24 is directly connected, Serial0/0
O 10.1.56.6/32 [110/64] via 10.1.56.6, 00:00:01, Serial0/0
O 10.1.56.5/32 [110/64] via 10.1.56.5, 00:00:01, Serial0/0
C 10.1.123.0/24 is directly connected, FastEthernet0/0

So do pay attention to the network type while configuring OSPF.