POINT_TO_MULTIPOINT means no DR/BDR election. This also signify that the hub sees each adjacency as a point-to point link and that the NEXT-HOP is always the HUB (so, partial mesh frame relay configuration is possible, for example dynamic mapping with no knowledge of the dlci to use to reach another spoke).
NON_BROADCAST means manual configuration of the neighbors. The costs can be specified on a per neighbor basis, through the neighbor command. This is useful on NBMA networks.
On r1:
!
interface Serial0/0
ip address 150.0.0.1 255.255.255.0
encapsulation frame-relay
ip ospf network point-to-multipoint non-broadcast
frame-relay map ip 150.0.0.2 102 broadcast
frame-relay map ip 150.0.0.3 103 broadcast
no frame-relay inverse-arp
!
router ospf 1
router-id 150.1.1.1
log-adjacency-changes
passive-interface Loopback0
network 150.0.0.1 0.0.0.0 area 0
network 150.1.1.1 0.0.0.0 area 0
network 150.10.0.11 0.0.0.0 area 0
neighbor 150.0.0.3
neighbor 150.0.0.2
!
r1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
150.3.3.3 0 FULL/ - 00:01:42 150.0.0.3 Serial0/0
150.2.2.2 0 FULL/ - 00:01:42 150.0.0.2 Serial0/0
r1#
On r2:
!
interface Serial0/0
ip address 150.0.0.2 255.255.255.0
encapsulation frame-relay
ip ospf network point-to-multipoint non-broadcast
frame-relay map ip 150.0.0.1 201 broadcast
frame-relay map ip 150.0.0.3 201
frame-relay map ip 150.0.0.4 201
no frame-relay inverse-arp
!
router ospf 1
router-id 150.2.2.2
log-adjacency-changes
passive-interface Loopback0
network 150.0.0.2 0.0.0.0 area 0
network 150.2.2.2 0.0.0.0 area 0
!
r2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
150.1.1.1 0 FULL/ - 00:01:54 150.0.0.1 Serial0/0
r2#
r2#show ip route ospf
150.0.0.0/16 is variably subnetted, 3 subnets, 2 masks
O 150.0.0.3/32 [110/128] via 150.0.0.1, 00:22:52, Serial0/0
O 150.0.0.1/32 [110/64] via 150.0.0.1, 00:22:52, Serial0/0
150.1.0.0/32 is subnetted, 1 subnets
O 150.1.1.1 [110/65] via 150.0.0.1, 00:22:52, Serial0/0
150.3.0.0/32 is subnetted, 1 subnets
O 150.3.3.3 [110/129] via 150.0.0.1, 00:22:52, Serial0/0
150.10.0.0/24 is subnetted, 1 subnets
O 150.10.0.0 [110/65] via 150.0.0.1, 00:22:52, Serial0/0
r2#
r2#show ip ospf interface Serial 0/0
Serial0/0 is up, line protocol is up
Internet Address 150.0.0.2/24, Area 0
Process ID 1, Router ID 150.2.2.2, Network Type POINT_TO_MULTIPOINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_MULTIPOINT
Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
oob-resync timeout 120
Hello due in 00:00:27
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 4 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 150.1.1.1
Suppress hello for 0 neighbor(s)
r2#show ip ospf database router 150.3.3.3
OSPF Router with ID (150.2.2.2) (Process ID 1)
Router Link States (Area 0)
LS age: 1704
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 150.3.3.3
Advertising Router: 150.3.3.3
LS Seq Number: 80000022
Checksum: 0xCD39
Length: 60
Number of Links: 3
Link connected to: a Stub Network
(Link ID) Network/subnet number: 150.3.3.3
(Link Data) Network Mask: 255.255.255.255
Number of TOS metrics: 0
TOS 0 Metrics: 1
Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 150.1.1.1
(Link Data) Router Interface address: 150.0.0.3
Number of TOS metrics: 0
TOS 0 Metrics: 64
Link connected to: a Stub Network
(Link ID) Network/subnet number: 150.0.0.3
(Link Data) Network Mask: 255.255.255.255
Number of TOS metrics: 0
TOS 0 Metrics: 0
There is a new stub network, 150.3.3.3 with mask 255.255.255.255 which is entered in the routing table as 150.3.3.3/32.
Note:
The mapping on the spoke is only necessary toward the HUB. Moreover, the broadcast keyword is optional.
The cost can be specified on a per neighbor basis.
On r1:
!
interface Serial0/0
ip address 150.0.0.1 255.255.255.0
encapsulation frame-relay
ip ospf network point-to-multipoint non-broadcast
frame-relay map ip 150.0.0.2 102
frame-relay map ip 150.0.0.3 103
no frame-relay inverse-arp
!
router ospf 1
router-id 150.1.1.1
log-adjacency-changes
passive-interface Loopback0
network 150.0.0.1 0.0.0.0 area 0
network 150.1.1.1 0.0.0.0 area 0
network 150.10.0.11 0.0.0.0 area 0
neighbor 150.0.0.3 cost 100
neighbor 150.0.0.2 cost 20
!
On r2:
!
interface Serial0/0
ip address 150.0.0.2 255.255.255.0
encapsulation frame-relay
ip ospf network point-to-multipoint non-broadcast
frame-relay map ip 150.0.0.1 201
no frame-relay inverse-arp
!
On r3:
!
interface Serial0/0
ip address 150.0.0.3 255.255.255.0
encapsulation frame-relay
ip ospf network point-to-multipoint non-broadcast
frame-relay map ip 150.0.0.1 301
no frame-relay inverse-arp
!
r1# show ip route ospf
150.0.0.0/16 is variably subnetted, 3 subnets, 2 masks
O 150.0.0.2/32 [110/20] via 150.0.0.2, 00:01:16, Serial0/0
O 150.0.0.3/32 [110/100] via 150.0.0.3, 00:01:16, Serial0/0
150.2.0.0/32 is subnetted, 1 subnets
O 150.2.2.2 [110/21] via 150.0.0.2, 00:01:16, Serial0/0
150.3.0.0/32 is subnetted, 1 subnets
O 150.3.3.3 [110/101] via 150.0.0.3, 00:01:16, Serial0/0
r1# show frame-relay map
Serial0/0 (up): ip 150.0.0.2 dlci 102(0x66,0x1860), static,
CISCO, status defined, active
Serial0/0 (up): ip 150.0.0.3 dlci 103(0x67,0x1870), static,
CISCO, status defined, active
r1#show ip ospf neighbor detail
Neighbor 150.3.3.3, interface address 150.0.0.3
In the area 0 via interface Serial0/0
Neighbor priority is 0 (configured 0), State is FULL, 13 state changes, Cost is 100
DR is 0.0.0.0 BDR is 0.0.0.0
Options is 0x52
LLS Options is 0x1 (LR)
Dead timer due in 00:01:47
Neighbor is up for 00:04:58
Index 2/2, retransmission queue length 0, number of retransmission 4
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 1, maximum is 1
Last retransmission scan time is 0 msec, maximum is 0 msec
Neighbor 150.2.2.2, interface address 150.0.0.2
In the area 0 via interface Serial0/0
Neighbor priority is 0 (configured 0), State is FULL, 13 state changes, Cost is 20
DR is 0.0.0.0 BDR is 0.0.0.0
Options is 0x52
LLS Options is 0x1 (LR)
Dead timer due in 00:01:47
Neighbor is up for 00:04:58
Index 1/1, retransmission queue length 0, number of retransmission 1
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 1, maximum is 1
Last retransmission scan time is 0 msec, maximum is 0 msec
r2#show ip route ospf
150.0.0.0/16 is variably subnetted, 3 subnets, 2 masks
O 150.0.0.3/32 [110/164] via 150.0.0.1, 00:01:17, Serial0/0
O 150.0.0.1/32 [110/64] via 150.0.0.1, 00:01:17, Serial0/0
150.1.0.0/32 is subnetted, 1 subnets
O 150.1.1.1 [110/65] via 150.0.0.1, 00:01:17, Serial0/0
150.3.0.0/32 is subnetted, 1 subnets
O 150.3.3.3 [110/165] via 150.0.0.1, 00:01:17, Serial0/0
150.10.0.0/24 is subnetted, 1 subnets
O 150.10.0.0 [110/65] via 150.0.0.1, 00:01:17, Serial0/0
r2#show frame-relay map
Serial0/0 (up): ip 150.0.0.1 dlci 201(0xC9,0x3090), static,
CISCO, status defined, active
r3#show ip route ospf
150.0.0.0/16 is variably subnetted, 3 subnets, 2 masks
O 150.0.0.2/32 [110/84] via 150.0.0.1, 00:01:50, Serial0/0
O 150.0.0.1/32 [110/64] via 150.0.0.1, 00:01:50, Serial0/0
150.1.0.0/32 is subnetted, 1 subnets
O 150.1.1.1 [110/65] via 150.0.0.1, 00:01:50, Serial0/0
150.2.0.0/32 is subnetted, 1 subnets
O 150.2.2.2 [110/85] via 150.0.0.1, 00:01:50, Serial0/0
150.10.0.0/24 is subnetted, 1 subnets
O 150.10.0.0 [110/65] via 150.0.0.1, 00:01:50, Serial0/0
r3#show frame-relay map
Serial0/0 (up): ip 150.0.0.1 dlci 301(0x12D,0x48D0), static,
CISCO, status defined, active
Note:
Since the beginning of the example, the loopback configured on each router is a /24 but a /32 is advertised. This is because loopback have always the LOOPBACK network type. To change this, use ip ospf network point-to-point.
On r3:
r3#show ip ospf interface Loopback 0
Loopback0 is up, line protocol is up
Internet Address 150.3.3.3/24, Area 0
Process ID 1, Router ID 150.3.3.3, Network Type LOOPBACK, Cost: 1
Loopback interface is treated as a stub Host
r2#show ip route 150.3.3.3
Routing entry for 150.3.3.3/32
Known via "ospf 1", distance 110, metric 165, type intra area
Last update from 150.0.0.1 on Serial0/0, 00:00:55 ago
Routing Descriptor Blocks:
* 150.0.0.1, from 150.3.3.3, 00:00:55 ago, via Serial0/0
Route metric is 165, traffic share count is 1
After configuring the network type:
!
interface Loopback0
ip address 150.3.3.3 255.255.255.0
ip ospf network point-to-point
!
r3#show ip ospf interface Loopback 0
Loopback0 is up, line protocol is up
Internet Address 150.3.3.3/24, Area 0
Process ID 1, Router ID 150.3.3.3, Network Type POINT_TO_POINT, Cost: 1
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
No Hellos (Passive interface)
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 2/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 0
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
Now, this route is seen as a /24 on r2:
r2#show ip route 150.3.3.3
Routing entry for 150.3.3.0/24
Known via "ospf 1", distance 110, metric 165, type intra area
Last update from 150.0.0.1 on Serial0/0, 00:00:05 ago
Routing Descriptor Blocks:
* 150.0.0.1, from 150.3.3.3, 00:00:05 ago, via Serial0/0
Route metric is 165, traffic share count is 1
These changes are reflected in the database:
r2#show ip ospf database router 150.3.3.3
OSPF Router with ID (150.2.2.2) (Process ID 1)
Router Link States (Area 0)
LS age: 54
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 150.3.3.3
Advertising Router: 150.3.3.3
LS Seq Number: 80000026
Checksum: 0xA75E
Length: 60
Number of Links: 3
Link connected to: a Stub Network
(Link ID) Network/subnet number: 150.3.3.0
(Link Data) Network Mask: 255.255.255.0
Number of TOS metrics: 0
TOS 0 Metrics: 1
Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 150.1.1.1
(Link Data) Router Interface address: 150.0.0.3
Number of TOS metrics: 0
TOS 0 Metrics: 64
Link connected to: a Stub Network
(Link ID) Network/subnet number: 150.0.0.3
(Link Data) Network Mask: 255.255.255.255
Number of TOS metrics: 0
TOS 0 Metrics: 0
