apples thunderbolt gigabit cable

Discussion in 'iMac' started by mikewitney, Jul 13, 2014.

  1. mikewitney, Jul 13, 2014
    Last edited: Jul 13, 2014

    mikewitney macrumors newbie

    Joined:
    Jul 13, 2014
    #1
    i have bought a gigabit cable and plugged it in and my gigabit switch is reporting it as a 100mbs connection .
    i tried to manually force it to 1000mbs but it will not connect or work at all then

    i have a imac 2012 with mavericks installed

    anybody can help that would be great
    [​IMG]
    [​IMG]
    [​IMG]

    when i manually select 1000mbs
    it stops working
    my mac is fully updated
     
  2. Thermonuclear macrumors 6502

    Joined:
    May 23, 2009
    #2
    Leave it set to "AutoSelect". Apparently it's connecting to a 100 Mbps peer which can't handle a 1 Gbps connection. This would be the case if the peer is a router like the older AirPort models who's LAN connections topped out at 100 Mbps with 10 Mbps as the fallback.

    It is highly unlikely that a 10/100/1000 Mbps Ethernet adapter would work at one of the speeds but not all of them.
     
  3. mikewitney thread starter macrumors newbie

    Joined:
    Jul 13, 2014
    #3
    as far as im aware its connected to a gigabit switch the make is
    HP ProCurve 1810G - 8 GE

    and the image above with the ports is a report from the switch port 1 and 2 is a server with twin RJ45 sockets and port 3 is my mac
     
  4. mmomega macrumors demi-god

    mmomega

    Joined:
    Dec 30, 2009
    Location:
    DFW, TX
    #4
    Are you using a CAT5e or CAT6 cable or CAT5?

    When you connect the ethernet cable directly into the iMacs built-in ethernet port, how does it report? 100Mbps, 1000Mbps ?
     
  5. mikewitney thread starter macrumors newbie

    Joined:
    Jul 13, 2014
    #5
    im not sure about the cable its 8 core straight through but when i connect to the macs port it reports as 100Mbps.
     
  6. mmomega macrumors demi-god

    mmomega

    Joined:
    Dec 30, 2009
    Location:
    DFW, TX
    #6
    So it's possible the Thunderbolt to Gigabit Ethernet adapter is working properly and the cable could be the culprit.

    If you are 100% certain that the switch is an HP 1810-8G then it is a full gigabit switch, if it is an HP 1810-8 then it is a 10/100 switch with 1 gigabit port.
    Next I would go buy BestBuy, WalMart, Radio etc or buy online a CAT5E or CAT6 cable.

    Cat5e and 6 for sure support gigabit speeds, while CAT5 can but is considered an obselete cable since 2001.

    Also if you or someone made the cable themselves it is possible that the pairs weren't terminated properly or the the twists weren't carried all the way to the ends correctly.
    Easiest thing to do is just get a replacement cable and test again.
     

Share This Page