Network brainteaser - a specific PC, when connected, always crashes the network

Discussion in 'Computer Information' started by Adam Steiner, Jan 23, 2004.

  1. Adam Steiner

    Adam Steiner Guest

    Hey,

    Got a real head scratcher.

    I have four computers hooked up to a Linksys router with a 4 port switch.
    Two of the computers (Compaq) are running Win2k Server, the other two are
    running XP Pro. But the network kept on crashing, to be more specific, the
    router would not route traffic to the internet within a couple of minutes of
    either Compaq (2k Server) being connected.

    I went ahead and formatted one of the Compaq's (I don't know why 2KServer
    was on in the first place) and installed XP Pro, thinking the problem may
    have to do with the operating system. But the same thing happend, within a
    couple of minutes of it being connected, the network would go down.

    The machine has 2 NIC's, one on the mobo and one PCI. It happens with every
    NIC, but when I took the PCI nic (a Realtek, mobo one is Intel) and put it
    into the XP machine, it worked flawlessly.

    Does anyone have any ideas? Could it just be that both motherboards are
    doing some strange things? I've checked and tested all the cables too.

    Thanks,
    Adam
     
    Adam Steiner, Jan 23, 2004
    #1
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  2. Adam Steiner

    DeMoN LaG Guest

    Try disabling/removing all the NICs from one of those machines, and
    swapping in a known working NIC from another machine. Then check if it
    still happens. It's possible the NICs in the machines you have are doing
    something funky.

    --
    AIM: FrznFoodClerk
    email: [email protected]_cast.net (_ = m)
    website: under construction
    Need a technician in the south Jersey area?
    email/IM for rates/services
     
    DeMoN LaG, Jan 23, 2004
    #2
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  3. Adam Steiner

    Adam Steiner Guest

    Tried it. The problem is I can't swap out the NIC on the mobo, but I did
    disable it. The whole thing is strange, no?

    --Adam
     
    Adam Steiner, Jan 23, 2004
    #3
  4. Adam Steiner

    DeMoN LaG Guest

    Have you tried hooking just the problem machines up to the router, perhaps
    using different ports on the router (perhaps one is faulty)?

    --
    AIM: FrznFoodClerk
    email: [email protected]_cast.net (_ = m)
    website: under construction
    Need a technician in the south Jersey area?
    email/IM for rates/services
     
    DeMoN LaG, Jan 23, 2004
    #4
  5. Adam Steiner

    Trent© Guest

    Which machine are you talking about?...that's givin' you the problem.
    How about givin' them some kind of designation for us...letters,
    maybe.

    Is the network down?...or just the Internet?

    Did you try pinging the router from each machine?...pinging each of
    the machines?

    How many machines have 2 NIC's? Did you try releasing and renewing
    the addresses?

    Let us know.


    Have a nice week...

    Trent

    If the cheese isn't yours...its Nacho cheese, man!
     
    Trent©, Jan 23, 2004
    #5
  6. Adam Steiner

    Adam Steiner Guest

    Yep. One of the computers was hooked up to a different network and was
    running fine for a couple of months. The only difference between the two
    networks was my network is running NAT and the other wasn't.

    --Adam
     
    Adam Steiner, Jan 23, 2004
    #6
  7. Adam Steiner

    Adam Steiner Guest

    Machine A, B - Compaq Presarios
    Machine C - Whitebox (XP Pro)
    Maachine D - Dell laptop XP Pro

    A, B originally had 2 NIC's each and were each running Server 2K. When
    hooked up to a linksys router the internet connection would die. Each
    machine can be reached via ping and each machine could log into the router.
    Once you clicked 'Save Settings' in the router things would work again for
    thirty seconds or so.
    Formatted A, put on XP Pro. Same thing. Took one of the NIC cards out of
    B and put it in C, NIC worked perfectly, no problems whatsoever.

    So it doesn't appear to be the NIC's, they work (at least the removable
    ones). Doesn't seem to be the OS because it's the same problem across XP
    and 2K. Happend with a DLink and 2 Linksys routers. Same problem whether
    DHCP was enabled on the routers or not. Only thing I can come up with is
    that something is screwy with the computers...but what I don't know.

    --Adam
     
    Adam Steiner, Jan 23, 2004
    #7
  8. Adam Steiner

    DH Guest

    If you only have the XP box on, will the Network go down. And is it the
    Network or the internet? What is your address before and after it goes
    down. Once it goes down, is your modem still communicating with your ISP?

    Let us know,

    Dave H.
     
    DH, Jan 23, 2004
    #8
  9. Adam Steiner

    Trent© Guest

    If you don't need both the on-board and the PCI NIC's, uninstall and
    take out the PCI NIC's. Make sure you disable DHCP in the operating
    systems...but not on the router.
    Die? Does that mean you'd be able to access the Internet for a period
    of time after you hooked up the Linksys?...and after a period of time
    you wouldn't? Or does that mean that when you hooked up the Linksys,
    you IMMEDIATELY wouldn't be able to access the Internet?
    So you went and got the address for each machine?...and pinged that
    address? Did you ping by name, too?
    Things? You need to be more specific. What worked?...what
    didn't?...SPECIFICALLY!
    Did you check Device Manager after the install? Did you get a notice
    that new hardware had been detected? Maybe the card never even got
    installed...hence, no conflict.

    I don't think its a computer problem. But it could be a router
    problem/conflict of some kind.

    Also, try resetting the router when this happens. But make sure you
    read the manual on how to do the reset.

    Run ipconfig before and after the problem...to see what has changed.

    Good luck...let us know.


    Have a nice week...

    Trent

    If the cheese isn't yours...its Nacho cheese, man!
     
    Trent©, Jan 24, 2004
    #9
  10. Adam Steiner

    Adam Steiner Guest

    Approximately thirty seconds to a minute after hooking up the Compaq's to
    the Linksys router, the connection to the Internet would die. It seems to
    happen as soon as the Compaq makes a request to the Internet. The first
    page loads, but everything after that, on the entire network, doesn't work.
    Ping by name, by address. Even after the connection to the internet died,
    the internal LAN would still work. The Compaq's (and other computers)
    despite not being able to access the internet, would be able to access the
    router.
    New card was installed and working.
    I'd tend to agree with you, but I can't figure out what the conflict would
    be with the router. I didn't see anything on the Linksys or DLink (tried
    one of their routers too) website. I did a hard reset on the router a few
    times, but it didn't help. All of the computers have valid IP's
    (192.168.1.*) both before and after the internet connection dies.

    To recap, the internet won't work, but the LAN is working fine. The
    computers can ping each other, and each computer can access the router, but
    nothing can access the internet.

    --Adam
     
    Adam Steiner, Jan 25, 2004
    #10
  11. Adam Steiner

    Adam Steiner Guest

    Yes, the network will still go down. The address stays the same, the LAN
    address for the desktop and the WAN address in the router. I even checked
    it from outside, people can see the router and it appears (at least from the
    outside) to be working.

    --Adam
     
    Adam Steiner, Jan 25, 2004
    #11
  12. Adam Steiner

    Trent© Guest

    And the default gateway hasn't changed any when you then run a
    ipconfig/all?

    Yer right...this is weird!! lol

    Am I correct that you now only have 1 NIC installed on each machine?
    Do you have DHCP disabled on the 4 computers?

    Did you check for any HOST files on the computers?

    After the problem, run the ipconfig to see that they have the proper
    gateway address.
    It really sounds like a gateway problem. But I'm a LONG way from
    being a networking expert! lol

    Good luck...let us know.


    Have a nice week...

    Trent

    If the cheese isn't yours...its Nacho cheese, man!
     
    Trent©, Jan 25, 2004
    #12
  13. Adam Steiner

    Adam Steiner Guest

    Hasn't changed, still working perfectly.
    Yep


    I'm thinking that when I look at the network again on Monday something will
    just hit me. Right now I'm getting tired of the squishy sound my head makes
    when it hits the desk :)
     
    Adam Steiner, Jan 25, 2004
    #13
  14. Adam Steiner

    Trent© Guest

    The addresses on each computer still point to the router? The user
    name and password is still in the router at this point?

    From what I can see, that's where the problem has somehow got to be.
    You've got a viable network...you just don't have access to the Net.

    Do a CAD on each machine when this happens...check your Processes to
    see if by chance DHCP is running.
    lol

    You might try one machine at a time...only use one port. Try each of
    the good machines first.

    You might do the same thing then by by-passing the router...and just
    go thru the modem. Make sure you turn DHCP back on when you do this.

    No Norton stuff installed to screw you up?...or anybody's firewalls?

    Good luck...let us know.


    Have a nice week...

    Trent

    If the cheese isn't yours...its Nacho cheese, man!
     
    Trent©, Jan 25, 2004
    #14
  15. Adam Steiner

    DeMoN LaG Guest

    What would a username have to do with internet access going down?
    DHCP doesn't show as process, Trent.
     
    DeMoN LaG, Jan 26, 2004
    #15
  16. Adam Steiner

    Trent© Guest

    If the name or password got hosed, the router won't be connected to
    the Net.
    Yer right...thanks.

    He'd hafta go into My Computer/Manage/Services & Apps/Services...and
    make sure its disabled.


    Have a nice week...

    Trent

    If the cheese isn't yours...its Nacho cheese, man!
     
    Trent©, Jan 26, 2004
    #16
  17. Adam Steiner

    DeMoN LaG Guest

    Actually, he would have to go to his network connection and under TCP/IP
    properties and see if he has specified his IP address or the radio button
    is on "Obtain IP address automatically"

    --
    AIM: FrznFoodClerk
    email: [email protected]_cast.net (_ = m)
    website: under construction
    Need a technician in the south Jersey area?
    email/IM for rates/services
     
    DeMoN LaG, Jan 26, 2004
    #17
  18. Adam Steiner

    Trent© Guest

    That part makes no difference. It has nothing to do with the gateway.


    Have a nice week...

    Trent

    If the cheese isn't yours...its Nacho cheese, man!
     
    Trent©, Jan 26, 2004
    #18
  19. Adam Steiner

    DeMoN LaG Guest

    It doesn't? Someone tell that to my dialog box when I specify my own IP.
    It has:
    IP address
    Subnet Mask
    Defalt Gateway

    Did I miss something here?

    --
    AIM: FrznFoodClerk
    email: [email protected]_cast.net (_ = m)
    website: under construction
    Need a technician in the south Jersey area?
    email/IM for rates/services
     
    DeMoN LaG, Jan 26, 2004
    #19
  20. Adam Steiner

    Adam Steiner Guest

    Primary and Secondary DNS servers, although you can obtain those
    automatically.

    Either way, in order to help end the thread, I set up the new computer to
    act as a router using ICS and then assigned static IP's to all the machines
    (needed that for seperate reasons) and now it seems to be working well.

    --Adam
     
    Adam Steiner, Jan 26, 2004
    #20
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