OSPF network types - Part 2

the physical topology remains the same:

But in this example all 3 routers are connected in full mesh topology, through the frame-relay cloud, which the default OSPF network type is NON-BROADCAST.

R1#sh ip ospf interface Serial0/0 is up, line protocol is up   Internet Address 10.1.123.1/24, 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 10.1.123.1   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 00:00:23   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) Loopback1 is up, line protocol is up   Internet Address 192.168.11.1/24, Area 0   Process ID 1, Router ID 192.168.11.1, Network Type LOOPBACK, Cost: 1   Loopback interface is treated as a stub Host

The attributes for this type of network are as follow:

LAS flooding – Unicast

Neighbor statement – Yes

DR/BDR Election – Yes

Timers – 30/120

Modify next-hop – No

Note that this type of network is the default for frame-relay physical and Point-to-Multipoint.

In order to accomplish adjacency between all three we will have to configure neighbor statements on each one of them.

R1:

R1#sh running-config | s ospf router ospf 1  log-adjacency-changes  network 10.1.123.1 0.0.0.0 area 0  network 192.168.11.1 0.0.0.0 area 0  neighbor 10.1.123.2  neighbor 10.1.123.3

The result:

R1#sh ip ospf neighbor Neighbor ID     Pri   State           Dead Time   Address         Interface 192.168.22.1      1   FULL/BDR        00:01:36    10.1.123.2      Serial0/0 192.168.33.1      1   FULL/DR         00:01:50    10.1.123.3      Serial0/0