serial and line protocol up and down constantly- 2811 pont to point to a 1700

Discussion in 'Cisco' started by RTR, Jun 29, 2005.

  1. RTR

    RTR Guest

    Hi guys
    Have a cisco 2811 with 2 serail point to point t1 one to ISP other one
    to remote location

    the remote location has a 1700 router. the connectivity is very flaky
    it keeps going up and down every few days and comes up and then goes
    down.
    2811 does NAT to get the remote location on internet.

    I checked on 2811 and did a show interface serial0/1/0:0

    I see that every 15 seconds this what is happening

    serial is up line protocol is up
    15 seconds later
    serial is down line protocol is down
    15 seconds later
    serial is up line protocol is down
    15 seconds later
    serial is up line protocol is up
    15 seconds later
    serial is down line protocol is down
    This cycle keeps going on and on.

    checked with the provider they are saying circuit is fine.
    ------------------------------------------------
    here is a output of sh interface command

    Serial0/1/0:0 is down, line protocol is down (both are going up and
    down)
    Hardware is GT96K Serial
    Description: ---> T1 to ASHBURN. PROVIDER: AT&T
    Internet address is 10.95.4.1/24
    MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,
    reliability 255/255, txload 1/255, rxload 1/255
    Encapsulation HDLC, loopback not set
    Keepalive set (10 sec)
    Last input 00:00:07, output 00:00:06, output hang never
    Last clearing of "show interface" counters never
    Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
    Queueing strategy: weighted fair
    Output queue: 0/1000/64/0 (size/max total/threshold/drops)
    Conversations 0/1/256 (active/max active/max total)
    Reserved Conversations 0/0 (allocated/max allocated)
    Available Bandwidth 1152 kilobits/sec
    5 minute input rate 0 bits/sec, 0 packets/sec
    5 minute output rate 0 bits/sec, 0 packets/sec
    2773 packets input, 153976 bytes, 0 no buffer
    Received 614 broadcasts, 0 runts, 1 giants, 0 throttles
    555832 input errors, 555832 CRC, 237655 frame, 132855 overrun, 0
    ignored, 417642 abort
    2816 packets output, 223809 bytes, 0 underruns
    0 output errors, 0 collisions, 48 interface resets
    0 output buffer failures, 0 output buffers swapped out
    433 carrier transitions
    Timeslot(s) Used:1-24, SCC: 0, Transmitter delay is 0 flags
    ------------------------------------------------------------------------

    Thanks

    RTR
    RTR, Jun 29, 2005
    #1
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  2. RTR

    Delija Guest

    Check clocking with your provider for remote location.
    Delija, Jun 29, 2005
    #2
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  3. RTR

    Guest Guest

    Seems to me to that is a layer 1 issue. your interface is restarting because
    is lossing keepalives (after lossing 3 keepalives in a row the interface
    will restart itself). Have you noticed that the carrier transitions are to
    the roof? What Delija said may be true, check all parameters agains your
    telco, make sure you have same encapsulation on both sides, if still failing
    do a loop test (follow this document
    http://cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a00800a754b.shtml
    make sure that you perform it creating the cable and not using the loopback
    command) if the test goes sucessfull on both sides there's no doubt is your
    telco.

    --
    2nd Law of Thermodynamics: Chaos will Reign.

    ///////////////////
    --Anthrax--
    //////////////////
    "RTR" <> wrote in message
    news:...
    > Hi guys
    > Have a cisco 2811 with 2 serail point to point t1 one to ISP other one
    > to remote location
    >
    > the remote location has a 1700 router. the connectivity is very flaky
    > it keeps going up and down every few days and comes up and then goes
    > down.
    > 2811 does NAT to get the remote location on internet.
    >
    > I checked on 2811 and did a show interface serial0/1/0:0
    >
    > I see that every 15 seconds this what is happening
    >
    > serial is up line protocol is up
    > 15 seconds later
    > serial is down line protocol is down
    > 15 seconds later
    > serial is up line protocol is down
    > 15 seconds later
    > serial is up line protocol is up
    > 15 seconds later
    > serial is down line protocol is down
    > This cycle keeps going on and on.
    >
    > checked with the provider they are saying circuit is fine.
    > ------------------------------------------------
    > here is a output of sh interface command
    >
    > Serial0/1/0:0 is down, line protocol is down (both are going up and
    > down)
    > Hardware is GT96K Serial
    > Description: ---> T1 to ASHBURN. PROVIDER: AT&T
    > Internet address is 10.95.4.1/24
    > MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,
    > reliability 255/255, txload 1/255, rxload 1/255
    > Encapsulation HDLC, loopback not set
    > Keepalive set (10 sec)
    > Last input 00:00:07, output 00:00:06, output hang never
    > Last clearing of "show interface" counters never
    > Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
    > Queueing strategy: weighted fair
    > Output queue: 0/1000/64/0 (size/max total/threshold/drops)
    > Conversations 0/1/256 (active/max active/max total)
    > Reserved Conversations 0/0 (allocated/max allocated)
    > Available Bandwidth 1152 kilobits/sec
    > 5 minute input rate 0 bits/sec, 0 packets/sec
    > 5 minute output rate 0 bits/sec, 0 packets/sec
    > 2773 packets input, 153976 bytes, 0 no buffer
    > Received 614 broadcasts, 0 runts, 1 giants, 0 throttles
    > 555832 input errors, 555832 CRC, 237655 frame, 132855 overrun, 0
    > ignored, 417642 abort
    > 2816 packets output, 223809 bytes, 0 underruns
    > 0 output errors, 0 collisions, 48 interface resets
    > 0 output buffer failures, 0 output buffers swapped out
    > 433 carrier transitions
    > Timeslot(s) Used:1-24, SCC: 0, Transmitter delay is 0 flags
    > ------------------------------------------------------------------------
    >
    > Thanks
    >
    > RTR
    >




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    Guest, Jun 29, 2005
    #3
  4. RTR

    RTR Guest

    Hi guys,

    I have done a loopback test using the loopback cable, i even tested the
    cable that is going to the demarc on both locations.
    No errors pings 100% and no input errors and no crc , on 1 side i got 1
    input error.
    Did the extended ping about 30- 50 time on both ends No errors at all.

    You guys mention about clocking, on one side the clocking is set to
    internal as this has a built in CSU/DSU. (Cisco2811)

    "Framing is ESF, Line Code is B8ZS, Clock Source is Internal."

    on the other side (cisco 1700) clocking is not set, I have run sh
    controller serila0 in order to see clocking.

    I am talking to the provider but they are trying to figure out what
    could be the problem on their side.
    what do u guys think.

    RTR
    RTR, Jul 8, 2005
    #4
  5. RTR

    Guest

    Verify with your loop provider that it is configured for clear-channel
    T1 and that framing and line code are set to ESF and B8ZS.

    We've had problems where the telco accidently re-provisioned links into
    the wrong framing or line code.

    Also, set both ends to take clocking from the network, otherwise you'll
    slowly accumulate framing errors.
    , Jul 9, 2005
    #5
  6. RTR

    risco

    Joined:
    Nov 1, 2007
    Messages:
    1
    SCTE problem.

    guys,

    if you check with "invert tx clock" command on serial if it is more than 2 mb link.
    risco, Nov 1, 2007
    #6
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