Subject: Re: ifmedia on fxp: can ifmedia defeat NWAY and force 10baseT?
To: Jonathan Stone <jonathan@DSG.Stanford.EDU>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: tech-kern
Date: 10/24/1999 10:08:15
On Fri, 22 Oct 1999 14:36:01 -0700 
 Jonathan Stone <jonathan@DSG.Stanford.EDU> wrote:

 > I have an fxp (EEPro 100+ client) connected to a NetGear 10/100 autosense hub.
 > I'm trying to use ifconfig's ifmedia support to throttle the card down
 > to 10Mbit/sec.  The lights on the NetGear still say the card is at 100Mbit,
 > even though ifconfig says the media type is now 10baseT.

...actually, the hub's lights say the hub is using 100TX for that port; they
say nothing about the link partner (except the "link" light, if your hub
has one).

 > Is this a bug in the MII code, or is what I'm trying to do not
 > supported by the hardware?

It's more likely a bug in the hub's firmware.  When you switch from 100 to
10, the 100 link goes into fail state, and the hub should detect this and
restart Nway; the PHY on the card, when hard-wired to 10T, advertises only
10T capability in its Nway code word.

Anyhow, the hub probably isn't restarting Nway.  This may be due to the
hub not properly detecting link fail.  Try unplugging the wire and plugging
it back in.

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>