Looking for some networking help...

Discussion in 'Community Discussion' started by GFLPraxis, Apr 3, 2011.

  1. GFLPraxis, Apr 3, 2011
    Last edited: Apr 3, 2011

    GFLPraxis macrumors 604


    Mar 17, 2004
    Wasn't sure where to put this as it isn't necessarily Mac related, but I was wondering if anyone could give me some tips on where to start on this.

    Here is a crude representation of my home's network topology (not to scale, especially locationwise):


    The router is a SMC router, 802.11n and Gigabit Ethernet. (Router and modem side of the wall are actually downstairs; the ISP's installer would not bring the line in upstairs, so the router had to be down).

    All of the cabling in wall is CAT6, and all of the short cables between devices and the wall are either CAT6 or CAT5e. My understanding is that both work fine for Gigabit Ethernet.

    Everything is set to Auto everywhere on both the router and the PC. PC is Gigabit (this is my motherboard: http://www.newegg.com/Product/Product.aspx?Item=N82E16813131025 )

    I omitted my MacBook (original 2 GHz Core Duo, white) from this, but it's normally connecting over WiFi. Same for iPad, iPhone, 3DS, Wii, printer, and other such devices.

    When I check Control Panel\Network and Internet\Network Connections (PC is running Windows 7; was a Hackintosh running Snow Leopard in the past, before a HDD failure, my first ever with a Western Digital), it shows that it is connected at 100 mbps.


    When I manually force the PC to 1000 mbps, it loses connectivity.

    The SMC Admin page on the router is set to auto.

    The switch (which is also SMC), I don't know if there is a way to configure. It's gigabit, but I don't believe it gets an IP address and don't what if any configurations there would be to change.

    I've got all of my media ripped and stream with Air Video (to my iPad) and PS3 Media Server (to my PS3/HDTV), including some 1080p video. I'm not sure if the performance bottleneck is my CPU or the network, but some 1080p movies stream poorly and get choppy across the network. I also intend to set up a NAS on the network, in which case gigabit speeds will matter a lot more.

    How can I get gigabit speeds on this PC? Does anyone have any suggestions on where I can start troubleshooting?
  2. Svend macrumors member

    Jan 27, 2010
    Check you patch cables. Cheap ones often omit 2 pair of wires, so you only have pins 1,2,3,and 6. This allows only for 100base-T. Make sure you see all 8 wires in the plugs. Check anywhere you have a physical connection. Also, move the switch or pc to eliminate the in house wiring to make sure it will negotiate at 1000base. My guess is one patch cable only has 4 wires.
  3. GFLPraxis thread starter macrumors 604


    Mar 17, 2004
    I know the in wall CAT6 has eight- I wired them. I just checked the little patch cables...they all seem to have eight :/
  4. yg17 macrumors G5


    Aug 1, 2004
    St. Louis, MO
    Let's try to eliminate some possible culprits here.

    Plug the cable that you have plugged into your PC into your MacBook (since it's more portable) and see if that will get a gigabit connection. If it does, it's likely your PC. If it doesn't, then we have some more variables to eliminate. Try a different cable from the wall to the MacBook. If it still fails, eliminate the wall and patch panel and try plugging your MacBook directly into the switch. Just keep narrowing things down until you get a gigabit connection, and then we'll know what the problem is and where to troubleshoot.

    Also, the problem is between the switch and your computer. If a PC is plugged into a gigabit switch, it will report a gigabit connection even if something upstream (like the router) is 100mbit. Based on that, it can be narrowed down to the switch, the wire to the patch panel, the patch panel itself, the in-wall wiring, or the wire from the wall to your PC.
  5. GFLPraxis thread starter macrumors 604


    Mar 17, 2004
    Thanks much for the assistance guys! Looks like it is one of the 1 foot cables between the switch and patch panels.

    I plugged the MacBook where my PC is plugged in, same 100 mbps. I plugged it in to my PS3's ethernet cable- 1 gbps. So then I went to the switch, and unplugged the little cable going from the switch to the patch panel port that corresponds with the PC, and plugged that in to the MacBook- 100 mbps.

    For giggles, I switched it out with another cable- bam, 1 gbps.

    Oddly, I can see all eight wires inside when I look at the head of the wire :/ Strange. But I guess the cheap patch cable was the culprit!

    To NewEgg! Thanks a million Svend and yg17 :)

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