How to troubleshoot this network issue

Discussion in 'Cisco' started by bensonlei, Apr 15, 2011.

  1. bensonlei

    bensonlei Guest

    Router log shows ( 10.10.10.2 is the peer router ):

    Apr 14 04:05:06.592 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.301 from FULL to DOWN, Neighbor Down: Dead timer
    expired
    Apr 14 04:05:06.812 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.340 from FULL to DOWN, Neighbor Down: Dead timer
    expired
    Apr 14 04:05:21.961 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.301 from EXSTART to DOWN, Neighbor Down: Dead timer
    expired
    Apr 14 04:05:21.961 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.340 from EXSTART to DOWN, Neighbor Down: Dead timer
    expired
    Apr 14 04:05:22.405 HKT: %OSPF-4-NONEIGHBOR: Received database
    description from unknown neighbor 10.10.10.2
    Apr 14 04:05:26.841 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.340 from LOADING to FULL, Loading Done
    Apr 14 04:05:29.725 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.301 from LOADING to FULL, Loading Done
    Apr 15 04:08:51.926 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.340 from FULL to DOWN, Neighbor Down: Dead timer
    expired
    Apr 15 04:08:52.539 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.301 from FULL to DOWN, Neighbor Down: Dead timer
    expired
    Apr 15 04:08:52.780 HKT: %HSRP-5-STATECHANGE: FastEthernet0/0.340 Grp
    40 state Standby -> Active
    Apr 15 04:08:53.028 HKT: %HSRP-5-STATECHANGE: FastEthernet0/0.301 Grp
    1 state Standby -> Active
    Apr 15 04:08:53.357 HKT: %HSRP-5-STATECHANGE: FastEthernet0/0.340 Grp
    40 state Active -> Speak
    Apr 15 04:08:53.413 HKT: %HSRP-5-STATECHANGE: FastEthernet0/0.301 Grp
    1 state Active -> Speak
    Apr 15 04:09:21.771 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.333 from EXCHANGE to DOWN, Neighbor Down: Dead timer
    expired
    Apr 15 04:09:21.779 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.301 from EXCHANGE to DOWN, Neighbor Down: Dead timer
    expired
    Apr 15 04:10:00.025 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.333 from LOADING to FULL, Loading Done
    Apr 15 04:10:07.530 HKT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on
    FastEthernet0/0.301 from LOADING to FULL, Loading Done


    Anybody finds any hint about this issue ?

    Thanks so much
     
    bensonlei, Apr 15, 2011
    #1
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  2. It could be so many different things, the logs you post are the end
    result, not the cause.

    Maybe you are dropping packets? Maybe the line goes down? Maybe your
    packets are scrambled? Maybe you have an MTU problem?

    Look at the error counters on the interfaces in question on both sides.
    Watch the interface status. Try running network traffic pattern
    tests and throughput tests. Make sure your packets get through unscrambled.
     
    Doug McIntyre, Apr 15, 2011
    #2
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  3. bensonlei

    bensonlei Guest

    Thanks so much for your suggestion.

    No CRC error for the interfaces so far, but only the overrun errors.
    And it should not be the MTU problem due to more than 10 sites are the
    same configuration without such problem.
    what else problems left ? scrambled packets --- any suggestion to
    test this issue ?
     
    bensonlei, Apr 15, 2011
    #3
  4. bensonlei

    Stephen Guest

    1st event is OSPF timeout - you have lost contact with the neighbour
    router over a vlan on Fa 0/0
    and another to the same neighbour, but on a different vlan over the
    same port.
    the OSPF adjacencies starting coming up but didnt make it (which seems
    a bit wierd and there dont seem to be all the log entries there should
    be)

    spanning tree or something interrupted the link after it bounced? -
    note if we knew what your ospf settings looked like we might
    understand what is happening better
    both back up
    and down again
    you have an ethernet link between 2 routers, and you are seeing either
    the neighbour router having problems, or the link between the 2 boxes.
     
    Stephen, Apr 15, 2011
    #4
  5. bensonlei

    bensonlei Guest

    Hi Stephen
    Thanks for the idea.

    Over than 10 sites have the same configuration, but only this site has
    such problem.
    The network supports mission critical system, so we set up the IPsec
    tunnel between HQ and each site ( so the MTU = 1476 );
    and also the hello-interval = 2 seconds; HSRP hello-interval =
    default...; we also support QoS for applications

    Any hint to find out the root cause ?
     
    bensonlei, Apr 18, 2011
    #5
  6. bensonlei

    Stephen Guest

    figuring out a log is a lot easier if you know the context.

    i dont think anyone can work out much more until you explain how your
    network is laid out and what is there
     
    Stephen, Apr 18, 2011
    #6
  7. bensonlei

    bitrob2005

    Joined:
    May 29, 2011
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    if you see now physical CRC or link errors on your side, check the peer device for errors or have the ISP check it. If you know there were no configuration changes then the issues has to be a physical one.
     
    bitrob2005, Jun 20, 2011
    #7
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