Subject: Re: Regarding 802.3u NWAY autonegotiation, hubs, media, etc.
To: Charles M. Hannum <>
From: Jason Thorpe <>
List: tech-net
Date: 12/09/1999 14:55:24
On 09 Dec 1999 17:18:41 -0500 (Charles M. Hannum) wrote:

 > It also seems like way too much magic.

I agree.  Yay, IEEE.

 > Perhaps the right thing to do is your point #1, but only long enough
 > to send a FLP to inform the other side (or for 5 seconds?), and then
 > switch to Parallel Detection.

I thought about that... but the problem is that when you clear BMCR_AUTOEN,
and the link goes down spuriously, the other side sees you're not capable
of NWAY.  So it falls back to Parallel Detection.

Now if you hardwired 100baseTX-FDX, you're screwed, because Parallel
Detection is defined to disallow detection of full-duplex.

        -- Jason R. Thorpe <>