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New Member

OSPF neigboring issue

Hi, I have configured my router to run OSPF and established adj with other routers (thru switch). However there are 2 routers that wont established the adj. It keep appears below log. It is in the same network/subnet. The MTU is 1500. What is other posibble things to check?

FastEthernet5/0/0 from 2WAY to DOWN, Neighbor Down: Interface down or detached

16 REPLIES

Re: OSPF neigboring issue

Mazlan,

Check the cable connection to fastethernet 5/0/0. There may be a speed/duplex issue which is causing the interface to go down and thus breaking your adjacency

HTH, rate if it does

Narayan

New Member

Re: OSPF neigboring issue

Narayan,

The connection is up. This interface also established ospf neigbor with other routers except 2 router. It keep stuck in exchange state. Also have check the MTU. It is same for all routers connected.

Re: OSPF neigboring issue

Mazlan,

If all the four routers are connected to a LAN segment, OSPF would choose a DR and BDR and all the routers would establish adjacencies only with these 2 routers.

But the status of the routers would not be in exchange but in a stae of 2-way..

Can you post your configurations

HTH, rate if it does

Narayan

Re: OSPF neigboring issue

HI Mazlan, [Pls Rate if Helps]

After creating / "Changing" a OSPF router id inorder to take effect you need to reload the router / reset the ospf process. Pls try cmd below:

#clear ip ospf process

Reset All OSPF Process[n]:yes

#show ip ospf neighbor

Pls Rate if Helps ! !

Best Regards,

Guru Prasad R

New Member

Re: OSPF neigboring issue

Hi guruprasadr,

Why I need to change router ID. This router has established neigbor with other routers as well. However i have tried this but still same. :(

--mazlan

Re: OSPF neigboring issue

Would it be possible for you to paste the sh ip ospf neighbors from all the 4 routers

Narayan

Re: OSPF neigboring issue

HI Mazlan,

Try this command twice / thrice. Can you please check by rebooting the router.

Number of LSA's should be same on all the Routers.Check with "show ip ospf database database-summary" cmd to observe.

Check "show ip ospf database" to check the LSA's on all routers.

Pls Rate if Helps ! !

Best Regards,

Guru Prasad R

New Member

Re: OSPF neigboring issue

Hi Prasad,

Thank you. I have check the number of LSA and it is same througout the network.

Area 0 database summary

LSA Type Count Delete Maxage

Router 116 0 0

Network 30 0 0

Summary Net 2393 0 0

Summary ASBR 269 0 0

Type-7 Ext 0 0 0

Prefixes redistributed in Type-7 0

Opaque Link 0 0 0

Opaque Area 4 0 0

Subtotal 2812 0 0

Re: OSPF neigboring issue

HI Mazlan,

Whether this solved your Issue. Can you pls confirm / post the configuration.

Pls Rate if Helped you to identify / solve.

Best Regards,

Guru Prasad R

New Member

Re: OSPF neigboring issue

Have you checked BFD, Fast Failure Detection to Speed Network Convergence

Check the following article:http://www.cisco.com/en/US/tech/tk365/technologies_white_paper0900aecd80244005.shtml

HTH: Steve

New Member

Re: OSPF neigboring issue

I have checked seems everything is ok. excpt it still wont established neigborship.. below logs keeps appears. have run debug i osf adj, the mtu is 1500.. any ideas??

May 21 16:47:50.754: %OSPF-5-ADJCHG: Process 1, Nbr 61.6.191.77 on GigabitEthernet0/0/0 from DOWN to DOWN, Neighbor Down: Dead timer expired

61.6.163.160 for invalid RP 161.142.158.14

May 21 16:49:11.431: %OSPF-5-ADJCHG: Process 1, Nbr 61.6.191.77 on GigabitEthernet0/0/0 from EXSTART to DOWN, Neighbor Down: Too many DBD retransmitions

Debup output:

May 21 16:51:32.417: OSPF: Retransmitting DBD to 61.6.191.77 on GigabitEthernet0/0/0

May 21 16:51:32.417: OSPF: 61.6.191.77 address 161.142.173.70 on GigabitEthernet0/0/0 is dead, state DOWN

May 21 16:51:32.417: %OSPF-5-ADJCHG: Process 1, Nbr 61.6.191.77 on GigabitEthernet0/0/0 from EXSTART to DOWN, Neighbor Down: Too many DBD retransmitions

May 21 16:51:33.388: OSPF: Nbr 61.6.191.77 161.142.173.70 GigabitEthernet0/0/0 is currently ignored

May 21 16:51:35.926: OSPF: Nbr 61.6.191.77 161.142.173.70 GigabitEthernet0/0/0 is currently ignored

May 21 16:51:38.641: OSPF: Nbr 61.6.191.77 161.142.173.70 GigabitEthernet0/0/0 is currently ignored

May 21 16:51:43.096: OSPF: Nbr 61.6.191.77 161.142.173.70 GigabitEthernet0/0/0 is currently ignored

Cisco Employee

Re: OSPF neigboring issue

Mazlan,

Can you try configuring "no capability lls" to see if it makes a difference.

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
New Member

Re: OSPF neigboring issue

Harold,

I have tried but still same. This router wont established neibor with one router.

It keep stuck at exstart state.

Cisco Employee

Re: OSPF neigboring issue

Mazlan,

Can you run a "deb ip ospf adj" on the opposite router as well.

Thanks,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
New Member

Re: OSPF neigboring issue

Harold,

Below is the output from opposite router when i run debug ospf adj.

May 21 21:27:49.603: OSPF: Up DBD Retransmit cnt to 3 for 61.6.191.77 on FastEthernet5/0/0

May 21 21:27:49.603: OSPF: Send DBD to 61.6.191.77 on FastEthernet5/0/0 seq 0xDAB opt 0x52 flag 0x7 len 32

May 21 21:27:54.603: OSPF: Retransmitting DBD to 61.6.191.77 on FastEthernet5/0/0

May 21 21:27:54.603: OSPF: Up DBD Retransmit cnt to 4 for 61.6.191.77 on FastEthernet5/0/0

May 21 21:27:54.603: OSPF: Send DBD to 61.6.191.77 on FastEthernet5/0/0 seq 0xDAB opt 0x52 flag 0x7 len 32

May 21 21:27:59.603: OSPF: Retransmitting DBD to 61.6.191.77 on FastEthernet5/0/0

New Member

Re: OSPF neigboring issue

Hi Mazlan,

What kind of switch u are using to connect routers, if it is manageable please check the VLAN configuration of switch, or please check the HELO and HOLD DOWN timers on routers.

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