Jonathan Stone addresses my network difficulties:

> First, if you manually configure full-duplex, you *MUST*
> manually configure full-duplex on the remote end of the point-to-point
> link (the switch port, or the other card if you're connecting two
> hosts via a crossover cable. Full-duplex to hubs cannot work, of course.)

Well, I didn't touch the switch, so presumably it is already configured
as full duplex.  (That switch is managed by another group.)

> Is this de0 hooked up to a less-than-brand-new Cisco, by any chance?

I am told that the switch is a "3com Superstack II switch 3300".

> Second: if you're using the de driver, presumably you're running
> NetBSD 1.4.1.  

Yes.

> I dont know about the 1.4 branch, but the MII drivers
> in -current, till about November 99, could get into a confused state
> when manually changing media speed. [...]
> The trick I found to fix it was to drop link pulse by ifconfig'ing the
> interface down. That forces the link peer to restart auto-negotiation,
> which usually ends up in a `good' state.  [...]
> My guess is, if you had tried writing a script which did the ifconfig
> up/ ifconfig down, without a sleep, that wouldn't have worked either.

I had tried, and it didn't.  The sleep is necessary, as you surmise.

> Third: if `ifconfig de0 media autosense' is failing to get to
> 100baseTX, 

I didn't explicitly try that.  I guess you mean "autoselect"?  There
is no "autosense" listed when I do "ifconfig -m".

I tested just now ("ifconfig de0 media autoselect"), and it just ends
up back in "media: Ethernet autoselect (10baseT)".

> then there's a bug, either in the de driver or in the
> switch at the far end.  Seems to me That's your real problem, and what
> you're asking for is a workaround for that. 

What I now *have* is a workaround for that.  :-)

> Is there any way you can
> try -current or the 1.4.2_ALPHA snapshots and see if those properly
> autosense to 100Mbit?

Realistically, not at this time.   Sorry about that.  :-(
And thanks for the help!


Anne.
-- 
Ms. Anne Bennett, Senior Analyst, IITS, Concordia University, Montreal H3G 1M8
anne@alcor.concordia.ca                                        +1 514 848-7606