Cat5 mystery

Discussion in 'Home Networking' started by =?iso-8859-1?q?C=2E_Se=F1or?=, Apr 26, 2006.

  1. I just bought a 1m Cat5 cable to connect between my PC and ADSL router to
    replace the 20m one. The router and PC are only 1/2 metre apart.

    I plugged it in, but the lights on the router and PC don't light up. I
    figure it's faulty but before sending it back I decide to make sure it is
    faulty I get a hub out and plug the two ends into two nodes but to my
    suprise it lights up! I tried from my hub to my PC, also works. Hub to my
    router also works. If I plug my 1m cat5 from my pc to my hub, then the 20m
    cat5 from my hub to my router I can access the Internet

    Here's some diagrams to explain:

    [PC]<----------- 1m cat5 --------->[Router] Doesn't work

    [PC]<----------- 20m cat5 -------->[Router] Works

    [Hub]<---------- 1m cat5 --------->[Hub] Works
    [Hub]<---------- 1m cat5 --------->[PC] Works
    [Hub]<---------- 1m cat5 --------->[Router] Works

    [Router]<- 20m cat5 ->[Hub]<- 1m cat 5 ->[PC] Works

    So, basically my new 1m cat5 will only work if it is plugged into my hub.
    If I simply plug it into my router and PC like I want it won't do
    anything, yet my other Cat5 cable does.

    Any ideas what could be causing this?
     
    =?iso-8859-1?q?C=2E_Se=F1or?=, Apr 26, 2006
    #1
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  2. =?iso-8859-1?q?C=2E_Se=F1or?=

    deKay Guest

    Soni tempori elseu romani yeof helsforo nisson ol sefini ill des Wed, 26 Apr
    2006 15:09:12 GMT, sefini jorgo geanyet des mani yeof do
    uk.comp.home-networking, yawatina tan reek esk C. Señor
    Looks to me like your cable is a crossover cable, and your hub auto-switches
    (but your router and PC don't).

    deKay
     
    deKay, Apr 26, 2006
    #2
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  3. I have to admit I didn't know about straight and crossover cables. The
    20m cable (that works) is crossover, the 1m isn't. I guess I need a 1m
    crossover cable instead.
     
    =?iso-8859-1?q?C=2E_Se=F1or?=, Apr 26, 2006
    #3
  4. =?iso-8859-1?q?C=2E_Se=F1or?=

    deKay Guest

    Soni tempori elseu romani yeof helsforo nisson ol sefini ill des Wed, 26 Apr
    2006 15:28:07 GMT, sefini jorgo geanyet des mani yeof do
    uk.comp.home-networking, yawatina tan reek esk C. Señor
    Yes - to connect the PC to the router it is likely you'll need a crossover
    (although this isn't the case with all routers).

    deKay
     
    deKay, Apr 26, 2006
    #4
  5. =?iso-8859-1?q?C=2E_Se=F1or?=

    linker3000 Guest

    You *shouldn't* need a crossover cable to connect a PC to an
    infrastructure device (switch, hub, router etc..) - but then again if
    you use one and it works who am I to complain!?
     
    linker3000, Apr 26, 2006
    #5
  6. Complete nonsense - exactly the opposite is true.
     
    Frazer Jolly Goodfellow, Apr 26, 2006
    #6
  7. No, he's right. To connect the (my) PC to the (my) router I will need a
    crossover cable, it even says in the manual a crossover cable is needed.

    Although for most routers a straight cable is needed it seems.
     
    =?iso-8859-1?q?C=2E_Se=F1or?=, Apr 27, 2006
    #7
  8. =?iso-8859-1?q?C=2E_Se=F1or?=

    linker3000 Guest

    Make and Model of your router?

    Name and shame!
     
    linker3000, Apr 27, 2006
    #8
  9. =?iso-8859-1?q?C=2E_Se=F1or?=

    deKay Guest

    Soni tempori elseu romani yeof helsforo nisson ol sefini ill des Wed, 26 Apr
    2006 22:56:12 GMT, sefini jorgo geanyet des mani yeof do
    uk.comp.home-networking, yawatina tan reek esk Frazer Jolly Goodfellow
    That depends on the router. Many wifi routers (with only one wired port) need
    a crossover. The one I installed for a guy who got it with his AOL
    connection, for example.

    There is no "always the case" regarding straight or crossover cables when it
    comes to ADSL or cable modems, routers, or other networking equipment, I've
    found. Usually, yes. Always, no. I have the exact same NTL cable modem as a
    friend, and mine uses a crossover if connected directly to a PC, my friend's
    does not.

    Besides, his evidence points to him needing a crossover.

    deKay
     
    deKay, Apr 27, 2006
    #9
  10. =?iso-8859-1?q?C=2E_Se=F1or?=

    deKay Guest

    Soni tempori elseu romani yeof helsforo nisson ol sefini ill des 27 Apr 2006
    09:28:57 -0100, sefini jorgo geanyet des mani yeof do uk.comp.home-networking,
    yawatina tan reek esk fornis do marikano es bono tan el:
    Going off the original poster's "experiments", it is likely his "hub"
    (probably actually a switch) does this.

    deKay
     
    deKay, Apr 27, 2006
    #10
  11. =?iso-8859-1?q?C=2E_Se=F1or?=

    usenet Guest

    More to the point lots of modern hardware (especially routers but I
    think also the PC end) auto-detects the direction of data and it won't
    matter at all whether you have a crossover cable or a straight through
    one, both will work.
     
    usenet, Apr 27, 2006
    #11
  12. =?iso-8859-1?q?C=2E_Se=F1or?=

    Alex Fraser Guest

    As far as I know, automatic detection of crossed/straight cable is required
    for gigabit Ethernet equipment. I have not heard of any "10/100" NICs that
    do it, but maybe some do. In addition to modern domestic routers, many
    switches also automatically detect the cable type.

    deKay's comment that "Many wifi routers (with only one wired port) need a
    crossover" is surprising and, in my opinion, pretty shameful.

    Why crossover cables were not specified throughout is a mystery to me,
    though the only specification I can think of that requires crossed cables is
    SCART (composite video and stereo audio in both directions are crossed).

    Alex
     
    Alex Fraser, Apr 27, 2006
    #12
  13. =?iso-8859-1?q?C=2E_Se=F1or?=

    Dave J. Guest

    Nice to see someone else with that question. I've pondered it since my
    earliest encounters with networking. If all sockets were wired the same
    then all connections would be crossover, no need to worry about which
    cable's which.

    Dave J.
     
    Dave J., Apr 28, 2006
    #13
  14. =?iso-8859-1?q?C=2E_Se=F1or?=

    Rob Morley Guest

    A switch /is/ a hub.
     
    Rob Morley, Apr 28, 2006
    #14
  15. =?iso-8859-1?q?C=2E_Se=F1or?=

    deKay Guest

    Soni tempori elseu romani yeof helsforo nisson ol sefini ill des Fri, 28 Apr
    2006 09:08:57 +0100, sefini jorgo geanyet des mani yeof do
    uk.comp.home-networking, yawatina tan reek esk Rob Morley
    Yes, but a hub is not a switch.

    deKay
     
    deKay, Apr 28, 2006
    #15
  16. =?iso-8859-1?q?C=2E_Se=F1or?=

    deKay Guest

    Soni tempori elseu romani yeof helsforo nisson ol sefini ill des Thu, 27 Apr
    2006 17:59:20 +0100, sefini jorgo geanyet des mani yeof do
    I'm assuming this is because most cable and ADSL modems (AFAIK) with an RJ45
    connection require a crossover to connect to a PC, and so the one-port wifi
    routers are simply modems with a wifi bit. Maybe.

    deKay
     
    deKay, Apr 28, 2006
    #16
  17. =?iso-8859-1?q?C=2E_Se=F1or?=

    nut Guest

    Is there a little button on the back of the router next to the port?

    If so, this button allows you to switch between straight and x-over...
     
    nut, Apr 28, 2006
    #17
  18. Not on the three routers of which I have experience. It is the factory
    reset button.

    But then all three of them detect crossover/straight through and act
    accordingly.
     
    Nicholas D Richards, Apr 28, 2006
    #18
  19. =?iso-8859-1?q?C=2E_Se=F1or?=

    usenet Guest

    Not strictly true, well I suppose it depends which way round you look
    at it. A switch does what a hub does plus some more so a switch is a
    'superset' of a hub.

    In reality there are very few hubs made now, nearly all (even the
    cheapest) are really switches.
     
    usenet, Apr 28, 2006
    #19
  20. =?iso-8859-1?q?C=2E_Se=F1or?=

    nut Guest

     
    nut, Apr 28, 2006
    #20
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