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veritasf6
Posts: 2
Registered: ‎03-18-2010

Network Cable Unplugged, even though it is not (this one is fun, I promise!)

I am plugging my computer into my Linksys router (this computer will not be connecting wirelessly).  Unfortunately my computer believes that the network cable is unplugged.  Allow me to provide some details before we continue!

 

Router: Linksys WRT54GL v1.1, with up-to-date firmware

Ethernet Card: Realtek PCIe GBE Family Controller (with up-to-date drivers)

Computer OS: Windows 7 64-bit 

 

And now for the fun part.  First, I figured that it was a bad ethernet cable, so I tried another, and another still.  The cable does not seem to be the problem.

 

Second, I figured that it may well be my ethernet card.  I plugged the ethernet cable from my cable modem directly in to my ethernet card and was instantly rewarded with a connection.  With that, I noted that my ethernet card is not the problem.

 

Third, I figured, well, it must be the router.  I tried the four ports on the back of the router to see if one was bad.  None of them worked.  The router does not show any lights for ports 1, 2, 3, or 4, no matter where I plug it in. Progress!  Certainly it is the router, right?  To make certain, I ran an ethernet cord from the router to a laptop and was rewarded once again with a connection.  So the router is not the problem.

 

After doing some reading both here and abroad, I reduced my "Speed & Duplex" to 10 Mbps Half Duplex.  That did not solve the problem.

 

Any and all help would be immensely appreciated, as I am rather frustrated.  Please let me know if I can provide any more information for you.  Thanks in advance for your help! 

Expert
Expert
Posts: 12,649
Registered: ‎07-16-2006

Re: Network Cable Unplugged, even though it is not (this one is fun, I promise!)

The problem with eletronics is that a device doesn't have to be dead but can be somewhat "off specifications" where it works with some devices and not with some others depending on how much "off spec" the other device accepts.

You could try to connect the laptop and desktop directly to each other with a ethernet cross-cable to see how they work together. Otherwise, you should try to replace either the router or the ethernet card to see if it makes the difference.
veritasf6
Posts: 2
Registered: ‎03-18-2010

Re: Network Cable Unplugged, even though it is not (this one is fun, I promise!)

Considering that RealTek is not exactly a small, unknown company, and that Linksys routers are supposed to work with RealTek NICs, I don't understand how the specifications can really be "off".  I'm in the process of locating an ethernet cross-cable to try, and will gladly share my results with the board, but buying a new router or a new NIC doesn't sound like a solution to the problem to me.  It sounds like ignoring the problem and doing something else.  Thanks for your help!
Expert
Expert
Posts: 12,649
Registered: ‎07-16-2006

Re: Network Cable Unplugged, even though it is not (this one is fun, I promise!)

No. I don't mean off spec in general. Just some devices in production fall through and pass QC even though there is some larger variance in the spec. Thus, a different piece of the same model may work differently then another. And it's difficult to find out where the problem is if two devices don't play well together because basically it could be either one. But just because one device works with one device and not with another does not tell you where the problem lies.

Testing a different router or a different NIC may be the only way to find out how to solve the problem. It's not ignoring the problem it's finding the problematic device. As you have noticed so far it's not that simple to find it.