Crossover cable - still needed?

Discussion in 'Networking and Wireless' started by Greg, Jul 8, 2008.

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  1. Greg

    Greg Super Moderator Super Moderator

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    So I want to connect two GigE network interfaces together to create a small two PC network. I'm not sure if a crossover cable is still required, or if the internal circuits auto-detect when the RX/TX lines should be swapped.

    ???
     
  2. Duct Tape Dude

    Duct Tape Dude Duct Tape Dude

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    I think routers generally auto-detect crossover cables, and PC's generally don't. I could very well be wrong, but I remember talk of that a year or two back--perhaps newer PC ethernet jacks are also auto-detecting.
     
  3. Meetloaf13

    Meetloaf13 fear the MONKEY!!!

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    I don't know if this helps, but I've had mixed success networking to computers with a regular cat5 cable...but it has worked.
     
  4. blue68f100

    blue68f100 Notebook Virtuoso

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    If the mfg added the detection in as per spec it should work. Some work some don't, give it a try and let us know.
     
  5. Wirelessman

    Wirelessman Monkeymod

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    You would normally need a crossover cable unless;

    Automatic crossover

    Automatic MDI/MDI-X Configuration is specified as an optional feature in the 1000BASE-T standard[1], meaning that straight-through cables will usually work between Gigabit capable interfaces. This feature eliminates the need for crossover cables, obsoletes the uplink/normal ports and manual selector switches found on many older hubs and switches, greatly reducing installation errors. Note that although Automatic MDI/MDI-X is generally implemented, a crossover cable would still be required in the occasional situation that neither of the connected devices has the feature implemented and enabled.

    Even for legacy 10/100 devices, many NICs, switches and hubs automatically apply an internal crossover when necessary. Besides the eventually agreed upon Automatic MDI/MDI-X, this feature may also be referred to by various vendor-specific terms including: Auto uplink and trade, Universal Cable Recognition and Auto Sensing.
     
  6. Greg

    Greg Super Moderator Super Moderator

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    Alright, I'll try a standard cable tonight.

    Question two: Is Cat5e good for GigE connections?
     
  7. Wirelessman

    Wirelessman Monkeymod

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    Absolutely, Cat5e is actually full spec for Giga Ethernet.
     
  8. nizzy1115

    nizzy1115 Notebook Prophet

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    Cat5e is fine for gig ethernet. However, on all the switches i set up i use a cross over cable between them. I also like to use a different colored cable (yellow) for cross over, and blue for between patch panels and switches. It looks much nicer that way and is easier to find cables...but i think your just doing it at your house so you probably don't have many devices, or even a patch panel.

    Err edit. i thought you were connecting 2 gig switches together.
     
  9. Greg

    Greg Super Moderator Super Moderator

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    Nope...just two GigE adapters. I think both are Broadcom ICs, which gave me hope that I didn't need a crossover.

    And it turns out that it looks like I do not need one :D. Just tried.

    Turns out I'm pretty lucky too...a random Cat5 cable I found allowed the two to auto-negotiate to a 1Gbps link...perfect.
     
  10. Wirelessman

    Wirelessman Monkeymod

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    Good for you, enjoy it ;)
     
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