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OSPF neigboring issue

mazlan.alatif
Level 1
Level 1

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 16

royalblues
Level 10
Level 10

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

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.

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

guruprasadr
Level 7
Level 7

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

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

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

Narayan

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

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

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

sdoremus33
Level 3
Level 3

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

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

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

Harold,

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

It keep stuck at exstart state.

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
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