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Network adapter behaves strangely

  1. May 9, 2007 #1
    My laptop has an integrated Intel gigabit network adapter. I get internet from a cable modem through a CAT5 shielded cable.
    The problem is that sometimes the connection drops and the computer freezes, and after a few moments the "network cable is unplugged" icon appears. Then I press ctrl+shift+esc to see the cpu usage and one of the cores is idle while the other displays a steady oscillatory pattern, and the HDD led blinks at the same frequency as the oscillation displayed on the cpu usage graph. The problem is solved by either disabling/enabling the network connecton or restarting the computer.
    This problem occurs at totally random moments. Sometimes it would pass 2 days without problem, other times it would happen two times in 5 minutes. I don't think it's a problem with either the NIC or the modem because if I connect the laptop to another identical modem the problem doesn't show, and if I connect another computer to the modem that computer doesn't show the problem.

    Could it be that noise is somehow getting in the cable (although it is shielded)? What would be the behavior of a network connection affected by noise?
  2. jcsd
  3. May 9, 2007 #2
    Could be many things some internet service provider disconnect you if they notice that your connection is idle or just disconnect you every now and again coz they can . like the same problem and at first it was hardware related. What you can do is download a program which basically keeps your connection alive by pinging a website ,however i do believe that some service supplier don't allow the use of these programs so read the small print.
    GOOGLE CONNEVTION KEEP ALIVE PROGRAM and you should find some free one's also Norton internet security has connection keep alive built in as a web tool accessible from the menu ,all you have to do is tick a box.

    I did also have a near identical problem like yours though but mine was due to a faulty ADSL MODEM that didn't like to work to hard and used to overheat and disconnect freezing my PC if i did some major downloading films etc at my full speed.
  4. May 9, 2007 #3
    He's using an RJ45 connector if it's a Cat5 quality cable ukmicky, which means it is either cable or DSL that he is running and there should be no need for a keep-alive type program.

    Autonantal, give us the specs of your computer (CPU speed, RAM, etc). How old is the laptop? What operating system are you using?
    Last edited: May 9, 2007
  5. May 9, 2007 #4
    I have a ThinkPad T60 with an Intel Core 2 Duo @ 1.66Ghz, 1GB RAM, runing on Windows XP Professional SP2.
  6. May 10, 2007 #5
    Hi Bored

    It depends as my broadband internet enters my pc via an RJ45 connecter even though it comes via the telephone line.

    Telephone line into router and then router into network card (RJ45)

    I use the connection keep alive which comes with norton ,if i dont my connection drops every twenty minutes or so.
    Last edited: May 10, 2007
  7. May 10, 2007 #6
    It is not my case. I have a cable modem and my connection should be always on.
  8. May 10, 2007 #7
    So should mine ,i dont dial up my connection its always on but my connection will drop if i am idle for to long which would often require me to restart my router and occasionally my pc if i dont use a connection keep alive .ISP'S do it to try and free up bandwidth when their is a high demand.
    In the settings of your router you may have a setting which you can change called"Maximum Idle Time". try changing it. if that dont work download a free connection keep alive program (theirs no harm in trying) get two in case the first one dont work. If that dont work check that your hard drive isn't turning off through the power saving option of your laptop. if that dont work ring your service provider. and moan. if that dont work then check that the connections the springy bits on the RJ45 PLUG are in good order and making good contact as if their not they can actually heat up and bend disconnecting your line for a few seconds (That's is actually another problem Ive had in the past as i bought a cheap cable.:)

    And if that dont work then ???????????????????????????????????????????
    Last edited: May 10, 2007
  9. May 11, 2007 #8
    Wow, I've never heard of anybody doing that before. How come you aren't on broadband yet? 56k is.. kind of.. outdated, you know?
  10. May 11, 2007 #9

    I do have broadband i have 16 meg broadband which comes over the phone line into my router and the router connects to my network card.

    I do remember 56k but that was a long time ago .When i first started going on the internet i think the standard was 14.4k Now that was slow.
  11. May 11, 2007 #10


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    What you have, ukmicky, is DSL. Your situation probably has nothing to do with the situation of antonantal.

    - Warren
  12. May 11, 2007 #11
    I don't have a router. I connect directly to the cable modem. I never had to use a connection keep alive on my desktop pc and it works fine. I think i'll go and try to change the modem because anyway it sometimes stops working and I have to power it off and on again and then it takes half an hour to assign me the ip address.
    Last edited: May 11, 2007
  13. May 11, 2007 #12


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    I've had cable modems which flip out and reset for no reason. I would suspect your cable modem first.

    - Warren
  14. May 11, 2007 #13
    I forgot about this one

    You may have something running in the background that you may or may not know about which is using up to much of your system resources which can then cause your network connection to fail.

    Try shutting down as many (processes)as possible using the task manager and see what happens.

    Also did you check to see if your hard drive is powering down when the PC is left to idle.

    Their is always a reason and it mostly tends to have nothing to do with the modem

    Also how is your modem powered . Is it USB, sometimes its possible If you have too many USB devices connected up or one which draws a lot of current the others will sometimes switch off and reset.
    Last edited: May 12, 2007
  15. May 11, 2007 #14
    If I connect the desktop PC to the modem, i make a network connection between the PC and the laptop, I share the internet connection on the PC and then I set the laptop to connect to the internet through the PC, the problem never occurs. This elliminates the laptop from the possible causes. So there must be a problem with the modem.
    The weird thing is that the PC doesn't have any problem when connected directly to the modem, and this would elliminate the modem too from the possible causes.
    Maybe the fact that the NIC on the laptop is 1000Mb/s has an impact on the modem.
    Anyway I'll try to change the modem and see what happens.
  16. May 11, 2007 #15
    Im afraid not as the PC is the machine running the modem not the laptop.All the laptop is doing is sending software instructions to your ISP.
    because their is no problem with your MODEM.
    Yes and no, things aint always that simple.

    What you've just explained their says to me that the modem is fine and the PC is fine but either their is a compatability problem with your laptop and the modem which means they are both working fine but just dont like each other or the laptop is unable to keep a connection running due to a intermitant hardware fault , software setting or a software process is running using up too much of the laptops system resources memory ,processor etc and not leaving enough for the modem /network connection to operate

    However you could buy a new modem and be in the same position or its possible you could buy a modem and if its a simple compatability problem you could get one which works simply because it is sligtly more compatable than the old one.

    Best bet is to borrow a modem from a friend.
    Last edited: May 12, 2007
  17. May 11, 2007 #16


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    Sorry ukmickey, but your post makes no sense and is riddled with misconceptions. I really suggest that you stop trying to help in this thread. No offense intended, but suggestions like "USB may not be able to keep up with the power demands of the modem" are just downright silly... especially since I've never seen a bus-powered cable modem.

    - Warren
  18. May 11, 2007 #17


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    Some ISPs use MAC Address authentication, which may prevent you from keeping a connection with a NIC that has a different MAC than the one that was initially registered at the ISP.
  19. May 11, 2007 #18


    So i take it you've never know a USB device to fail occasionally during use due to the USB not being able to supply it with with enough power, I have even if you aint and i had a modem which it happened to.

    Also i said " how is your modem powered . Is it USB" because I forgot he was connecting up via an RJ45 connecter and was unsure if his cable modem was USB powered ,as you do get USB cable modems believe it or not.
    Last edited: May 12, 2007
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