OSPF in Frame-relay point-to-multipoint

Lab topology is hub and spoke, where R1 is the spoke and R3 and R4 are the spokes.

 

First I configured R2 as frame-relay switch:

frame-relay switching ! interface Serial0/0  no ip address  encapsulation frame-relay  clock rate 2000000  frame-relay lmi-type cisco  frame-relay intf-type dce  frame-relay route 103 interface Serial0/1 301  frame-relay route 104 interface Serial0/2 401 ! interface Serial0/1  no ip address  encapsulation frame-relay  clock rate 2000000  frame-relay lmi-type ansi  frame-relay intf-type dce  frame-relay route 301 interface Serial0/0 103 ! interface Serial0/2  no ip address  encapsulation frame-relay  clock rate 2000000  frame-relay lmi-type cisco  frame-relay intf-type dce  frame-relay route 401 interface Serial0/0 104 !

The configure R1 in point-to-multipoint manner:

interface Serial0/0.1 multipoint  ip address 10.1.134.1 255.255.255.0  snmp trap link-status  no arp frame-relay  frame-relay map ip 10.1.134.3 103 broadcast  frame-relay map ip 10.1.134.4 104 broadcast  frame-relay interface-dlci 103  frame-relay interface-dlci 104  no frame-relay inverse-arp !

And R3 and R4 in point-to-point manner: 

R3: interface Serial0/0  no ip address  encapsulation frame-relay  clock rate 2000000 ! interface Serial0/0.1 point-to-point  ip address 10.1.134.3 255.255.255.0  snmp trap link-status  frame-relay interface-dlci 301    no arp frame-relay  no frame-relay inverse-arp !

R4: interface Serial0/0  no ip address  encapsulation frame-relay  clock rate 2000000 ! interface Serial0/0.1 point-to-point  ip address 10.1.134.4 255.255.255.0  snmp trap link-status  no arp frame-relay  frame-relay interface-dlci 401   !

Then configuring OSPF on all 3 routers advertising loopback 1 and serial0/0.1 on each, waiting few minutes and nothing happen…no adjacency, no neighbors!

Let’s look on R1 OSPF interface:

R1#show ip ospf interface serial 0/0.1 Serial0/0.1 is up, line protocol is up   Internet Address 10.1.134.1/24, Area 0   Process ID 1, Router ID 192.168.11.1, Network Type NON_BROADCAST, Cost: 64   Transmit Delay is 1 sec, State DR, Priority 1   Designated Router (ID) 192.168.11.1, Interface address 10.1.134.1   No backup designated router on this network   Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5     oob-resync timeout 120     Hello due in 00:00:05   Supports Link-local Signaling (LLS)   Index 1/1, 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)

And on R3 OSPF interface:

R3#show ip ospf interface serial 0/0.1 Serial0/0.1 is up, line protocol is up   Internet Address 10.1.134.3/24, Area 0   Process ID 1, Router ID 192.168.31.1, Network Type POINT_TO_POINT, Cost: 64   Transmit Delay is 1 sec, State POINT_TO_POINT,   Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5     oob-resync timeout 40     Hello due in 00:00:05   Supports Link-local Signaling (LLS)   Index 1/1, 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)

See the problem…

In order to solve the problem I will change the topology to on all routers to OSPF network type to point-to-multipoint which is the most ideal for NBMA topology:

R1-R3-R4: interface Serial0/0.1  ip ospf network point-to-multipoint !

The result:

-          All updates are multicast

-          No DR/BDR election

-          Timers 30/120

-          No neighbor statements

-          Modify next-hop occurs

R4#show 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 O    192.168.31.0/24 [110/129] via 10.1.134.1, 00:03:26, Serial0/0.1      192.168.11.0/32 is subnetted, 1 subnets O       192.168.11.1 [110/65] via 10.1.134.1, 00:03:26, Serial0/0.1 C    192.168.41.0/24 is directly connected, Loopback1      10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks O       10.1.134.1/32 [110/64] via 10.1.134.1, 00:03:26, Serial0/0.1 C       10.1.134.0/24 is directly connected, Serial0/0.1 O       10.1.134.3/32 [110/128] via 10.1.134.1, 00:03:26, Serial0/0.1

Next lab – OSPF PtP partial mesh.