Ethernet Issue...Wireless=25/Mbps; Ethernet=2.5/Mbps

Discussion in 'iMac' started by Tofray, Jan 17, 2013.

  1. Tofray, Jan 17, 2013
    Last edited: Jan 17, 2013

    Tofray macrumors regular

    Mar 7, 2011
    My Netgear WNDR3700 Wireless N router was connected to my PC via ethernet, and was getting around 25/Mbps consistently. My iMac was connected wirelessly and was still getting around 23-24/Mbps.

    I decided I was going to connect the modem/router to the iMac, via ethernet, and now I'm only getting 2.5/Mbps. I've checked the connections 3 times, have scoured over the router manual and Netgear website, and can't figure it out. I've gone over my router settings line by line, and they look perfectly normal. My ping is only 9, whereas on wireless it was around 30.

    Also, in Network Utility, my Link Speed shows as 1 Gbit/s...Is that right? I always thought it was 10 or 10/100.

    Anyone have any ideas?
  2. Gav2k macrumors G3


    Jul 24, 2009
    Bad cable
  3. bmcgrath macrumors 65816


    Oct 5, 2006
    London, United Kingdom
    Trying a different cable is a good start.

    Next - Check the configs on the router itself and make sure everything looks alright.
  4. glintoz macrumors newbie

    Oct 29, 2012
    Speed & Duplex Settings

    Try a different port on the router.

    Also, make sure that the ports on each end of the link are set to auto-negotiate link speed and duplex. If you get a duplex mismatch you will end up with a low data rate.

    If the speed is wrong usually the link doesn't come up at all.

    Otherwise probably a bad cable.
  5. Tofray thread starter macrumors regular

    Mar 7, 2011
    Thanks for the suggestions, guys. I'll try some new Ethernet cables. Could it be a bad coaxial cable too? (I'm on broadband)

    When I installed the modem/router, I tucked all of it underneath my desk and tried to hide them all. In doing so, they are definitely kinked up tightly, so maybe I'll loosen them up and see if it makes a difference.
  6. jmpage2 macrumors 68040


    Sep 14, 2007
    If the broadband was the problem you would get the same bad speeds on both wired and wireless.

    Another thing you can do is see what link speed your Mac is negotiating the wired connection. From terminal;

    ifconfig en0 | grep media

    media: autoselect (1000baseT <full-duplex,flow-control>)

    Output might show that your link is negotiated at the wrong speed or at half duplex in which case you have a bad cable or an incompatibility between switch and Mac.

    You also might have errors on the interface;

    netstat -e | grep en0

    and see if you have iERRs or oERRS
  7. Tofray thread starter macrumors regular

    Mar 7, 2011
    Man, I feel like such a dummy...After spending hours researching the problem online, going line by line on each router configuration, reading the router/modem manuals twice, and then ultimately changing every single ethernet & coaxial cable, I realized what an idiot I am...

    I was using a cable splitter to split the cable to my TV & modem, and realized that I plugged the cable from the wall into an "out" plug instead of the "in" plug on the splitter. So all the "rechecking" of the wires I did was basically to look at the same problem over and over, without recognizing or changing it. I didn't think that would be the culprit, as I assumed I wouldn't get any signal at all if the ports were mixed up. But there ya go..

    Thanks for the help, people, and sorry to waste your time.

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