Re: Question: Etherenet Link Detection

[Randy.Dunlap]

Hi-

It's traditionally been defined as MII information, but that's
awfully slow, so some Ethernet controllers make it available
in a quicker manner.

ethtool might do this (http://sourceforge.net/projects/gkernel/);
I don't know for sure.

or mii-diag (http://www.scyld.com/diag/).

~Randy

Matthew Dharm wrote:
> 
> You can get that information from the PHY too, so if you can get to the MII
> control registers, you can query the phy for link status.
> 
> Again, tho, the problem is getting that data to userland.
> 
> Matt
> 
> On Fri, Sep 28, 2001 at 01:36:07AM +0200, Peter Sandstrom wrote:
> > I know for sure that the Intel 82559 Fast Ethernet embedded controller
> > has a register where it's possible to read out if the link led is active
> > or not. It seems quite likely that this would be available on other
> > controllers as well.
> >
> > Is there any functionality in the current kernel that enables a userland
> > program to read this? I mostly turn my machines on and and let them do
> > their thing until the hardware fails :)
> >
> > /Peter
> >
> > -----Original Message-----
> > From: [e-mail]
> > [mailto:[e-mail]]On Behalf Of Robert Cantu
> > Sent: den 26 september 2001 23:41
> > To: [e-mail]
> > Subject: Question: Etherenet Link Detection
> >
> >
> > Is there a method of detecting the link status of an ethernet NIC? If not,
> > is it feasible? And if it is, then would it be something in each driver,
> > or on a level above the driver, thereby available to all drivers? I figure
> > the list is the best place to ask this, although it might be a moot point.
> >
> > Example: Have a cable modem hooked into a computer's NIC. Cable service
> > goes out, link light on back of NIC goes out. A hypothetical program says
> > that the link is gone via some hook in /proc somewhere.
> >
> > Is this a worthwhile endeavor, if possible?