OSPF Network Type Non-Broadcast

[parthrawat979]

A simple topology of three routers R1, R2 and R3 connected in a multiaccess segmetn.

R1#sh ip os int f0/0
FastEthernet0/0 is up, line protocol is up
Internet Address 123.1.1.1/24, Area 0, Attached via Network Statement
Process ID 1, Router ID 1.1.1.1, Network Type NON_BROADCAST, Cost: 1
Topology-MTID Cost Disabled Shutdown Topology Name
0 1 no no Base
Transmit Delay is 1 sec, State DR, Priority 1
Designated Router (ID) 1.1.1.1, Interface address 123.1.1.1
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 00:00:17
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 1/1/1, flood queue length 0
Next 0x0(0)/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)
R1#sh ip os ne

Neighbor ID Pri State Dead Time Address Interface
N/A 0 ATTEMPT/DROTHER - 123.1.1.2 FastEthernet0/0
N/A 0 ATTEMPT/DROTHER - 123.1.1.3 FastEthernet0/0

R2#sh ip os int f0/0
FastEthernet0/0 is up, line protocol is up
Internet Address 123.1.1.2/24, Area 0, Attached via Network Statement
Process ID 1, Router ID 2.2.2.2, Network Type NON_BROADCAST, Cost: 1
Topology-MTID Cost Disabled Shutdown Topology Name
0 1 no no Base
Transmit Delay is 1 sec, State DR, Priority 1
Designated Router (ID) 2.2.2.2, Interface address 123.1.1.2
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 00:00:04
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 1/1/1, flood queue length 0
Next 0x0(0)/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)
R2#sh ip os ne

Neighbor ID Pri State Dead Time Address Interface
N/A 0 ATTEMPT/DROTHER - 123.1.1.1 FastEthernet0/0
N/A 0 ATTEMPT/DROTHER - 123.1.1.3 FastEthernet0/0

R3#sh ip os ne

Neighbor ID Pri State Dead Time Address Interface
N/A 0 ATTEMPT/DROTHER - 123.1.1.2 FastEthernet0/0
N/A 0 ATTEMPT/DROTHER - 123.1.1.1 FastEthernet0/0
R3#sh ip os int f0/0
FastEthernet0/0 is up, line protocol is up
Internet Address 123.1.1.3/24, Area 0, Attached via Network Statement
Process ID 1, Router ID 3.3.3.3, Network Type NON_BROADCAST, Cost: 1
Topology-MTID Cost Disabled Shutdown Topology Name
0 1 no no Base
Transmit Delay is 1 sec, State DR, Priority 1
Designated Router (ID) 3.3.3.3, Interface address 123.1.1.3
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 00:00:29
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 1/1/1, flood queue length 0
Next 0x0(0)/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 coun

why I am getting this Attempt state on every router I have ran
int f0/0
ip ospf network non-broadcast
and also 
router ospf 1 
neighbor 123.1.1.2
neighbor 123.1.1.3(on R1 and similar on every router)

[balaji.bandi]

When I look at your show output,  all showing DR

how are these all router-connected via a Layer 2 switch? Do you have any diagrams?

Can they ping each other to check? do you have any loopback configured with 1.1.1.1 and 2.2.2.2 so on ?

I will make a simple configuration like yours, but add the following as an addition and test it.

int f0/0

IP OSPF network non-broadcast
 
router ospf 1 

network 123.1.1.0 0.0.0.255 area 0

network 1.1.1.1 0.0.0.0 area 0

neighbor 123.1.1.2
neighbor 123.1.1.3

and test - if you have still issue run debug 

debug ip ospf hello

[parthrawat979]

Yeah they all are connected with a layer 2 switch and yes I have configured loopback on all the routers.

[balaji.bandi]

Can they ping each other to check? 

add additional config i provided and check also provided the debug output and ping output.

[parthrawat979]

No they can't ping each other.

[parthrawat979]

R1#ping 123.1.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 123.1.1.2, timeout is 2 seconds:
.
*Nov 9 15:43:25.119: OSPF-1 HELLO Fa0/0: Send hello to 123.1.1.3 area 0 from 123.1.1.1
*Nov 9 15:43:25.119: OSPF-1 HELLO Fa0/0: Send hello to 123.1.1.2 area 0 from 123.1.1.1....
Success rate is 0 percent (0/5)
No response from the neighbors.

[balaji.bandi]

R1#ping 123.1.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 123.1.1.2, timeout is 2 seconds:
.

i do not see the ping, you mentioned switch in between is this correct ?

on the the switch are you able to see show cdp neigh ?

what is the goal of testing this ? Frame relay ?

understand the use case of non-broadcast :

https://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/13690-18.html?referring_site=bodynav

General troubleshooting guide :

https://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/13699-29.html

[parthrawat979]

Yeah it's for understanding non-broadcast only.

[balaji.bandi]

If you understand, you also need to know how to troubleshoot here and provide enough information to help, rather than just one line.

basic principle of a network to reach others' IP addresses by  ping each other.,

[Joseph W. Doherty]

why I am getting this Attempt state on every router I have ran

Why are you configuring ip ospf network non-broadcast on a multi-access segment?

[M02@rt37]

Hello @parthrawat979 

Because you configure the interface as OSPF non-broadcast, so it disable multicast hellos. Each router keeps trying to reach its manually configured neighbors but never receives a hello back, so adjacencies never form.

Fix it by remove the non-broadcast setting and use the correct network type... mean broadcast, the default behavior.

[parthrawat979]

What kind of solution is this?? I want to be it a non-broadcast.

[M02@rt37]

Hello @parthrawat979 

Each router can ping the others on their respective interface ?

[parthrawat979]

No, they can't.

[Giuseppe Larosa]

Hello @parthrawat979 ,

if the routers cannot ping on the interfaces using the IP address in 123.1.1.0 subnet check the configuration of the L2 switch all the ports must be in the same L2 VLAN.

Once you solve basic connectivity issues you can go on with OSPF configuration and troubleshooting.

Hope to help

Giuseppe