On Wed, 27 Sep 2006, Rick Jones wrote:

quoted

Another scenario: forcing the NIC to negotiate only full-duplex speeds. Not
only fun if you try it against a hub, but possibly useful.

[...]

I'm just worried (as in Fear Uncertainty and Doubt) that having people set the
allowed things to negotiate isn't really any more robust than stright-up
hardcodes and perpetuates the (IMO) myth that one shouldn't autoneg on general
principle.

 Older equipment, which may still be in use here and there, allowed 
full-duplex operation, but no auto-negotiation.  The duplex setting was 
either fixed or selectable in a system-specific manner.  In such a case 
you certainly want your modern other end to be forced to full-duplex, but 
still let it detect the link speed, so that you do not have to do 
reconfiguration whenever you move a link between a 10base-T and a 
100base-Tx port.

  Maciej