Network Problem

[Eric Diamond]

Monday, April 19, 2004 4:09 PM Sébastien Bisoglio replied with:

> Taylor, ForrestX wrote:
> > On Mon, 2004-04-19 at 14:06, Sébastien Bisoglio wrote:
> >>on my switch the 100 led is ok.
> > 
> > Are you certain that it is saying 100Mb?  I have seen 
> several switches 
> > that have a slightly different color for 10/100.
> > 
> Yes for sur ! My old Linux Mandrake server is ok at 100 mbits 
> and led is 
> ok too !
> 
> After this command :
> 
> mii-tool -v -F 100baseTx-FD
> 
> Result :
> 
> [root at bisol root]# mii-tool
> eth0: 10 Mbit, full duplex, link ok

Hmmm, had a poster with a similar problem last week. It seemed to come
down to either a problems with mii-tool and ethtool or a problem with
the mii interface in the NIC driver. I put my money on the driver as
both mii-tool and ethtool work for myself and others.

However, I think this same advice should pertain to you both. Just
because the software interface is returning incorrect information
doesn't mean that the mii hardware isn't doing it's job. Link
negotiation happens at the hardware level even without the presence of a
driver. WOL cards maintain link even when the machines they are in are
powered off. Software, if properly implemented, can allow you to query
and sometimes even set mii parameters, but usually this is best left to
the hardware.

Does your NIC have both link and speed leds? If so, what speed do they
indicate? I would be willing to be they show 100Mbps. In this case, I
would trust what the hardware is telling you and not what the software
is telling you.

Mind you, I don't think it's good that mii-tool and ethtool are
reporting faulty information, but I do think that if you dig deep
enough, you're going to find that the problem is with the NIC and the
available driver. You might check the manufacturers page to see if there
are any known problems with linux in general and fedora in particular.
While you're there, look into the manufacturers policy on linux support
and also their usage of hardware tweaks. Not all OEM chipsets are
created equal.

BTW, what NIC are you using?

Eric Diamond
eDiamond Networking & Security
303-246-9555
eric at ediamond.net