Network Problem

[Tom 'Needs A Hat' Mitchell]

On Mon, Apr 19, 2004 at 11:00:01PM -0600, Eric Diamond wrote:
> Monday, April 19, 2004 10:44 PM Tom 'Needs A Hat' Mitchell
> > 
> > Tinker with  mii-tool.
> > Specifically 
> > 	     
> >  mii-too  --advertise=media interface
> > 
> >  media can be one of: 100baseT4, 100baseTx-FD,100baseTx-HD,  
> > 10baseT-FD, and 10baseT-HD.
> > 
> > What you should see is the link light go dark for a blink 
> > then a new physical layer connection is made.  It could be 
> > that the negotiation is not good and kicking it again might 
> > link up ....  I am finding that FD is hard for many 
> > inexpensive cards, switches and drivers.
> 
> I don't know about that. The problem is not that he can't get a link, he
> is and the connection is up at 100Mb/s, but mii-tool says it's only
> 10Mb/s.
...
> As for full duplex having poor support on cheaper hardware, I can easily
> believe that.

Right... he is seeing a slow link that is also being reported as a
slow link by mii-tool.  This tells me that what the LEDs are stuck or
something.  Perhaps the link needs to be kicked into gear any gear to
get hardware, LEDs  and software all on the same page.

The LEDs "should" blink as the new rate is negotiated.  This part
could be important and give us hints about driver issues.  Not all
drivers support the layer that mii-tool uses.  Perhaps some logic is
stuck and...

It may be worth the effort to force it into slow 10baseT-HD one time
them kick it up a notch....

Lastly do not ignore the posibility of a bad cable.  Watchout for
ports that have double plugs.  A four port hub often has five
connectors, one is cross wired so a null connection cable is not
needed.

Snoop on the link for IP error symptoms even if the hardware is not
reporting errors.

In general 'forcing' links presents problems because both ends need to
play the same games or nothing works.  Double check the other end too.
Tidy up when done tinkering.


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	T o m  M i t c h e l l 
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