On Tue, Oct 31, 2000 at 05:12:20AM -0500, Mark Abene wrote:
> 
> I have two hubs in two different rooms.  The "A" hub has a half-dozen different
> machines, including the sun3.  I just did a test, and enabled SQE on the sun3's
> transceiver.  Hub "B" is disconnected from hub "A".  The throughput of file
> transfers between the sun3 and other machines on the same hub has dramatically
> increased.  But between any other two machines on the same hub, it's horrible.
> Tons of collisions.  If I disconnect the sun3 from hub "A", everything is
> normal again.
> 
> Now, I connect hub "B" to hub "A", without the sun3.  Hub "B" has the sun4, and
> a freebsd/intel machine.  While hub "B" is connected to hub "A", there are
> tons of collisions.  Whether between machines on hub "A", or machines on hub
> "B" to "A".  Reconnecting the sun3 to hub "A" just makes things worse.
> If I disconnect the sun3, and hub "B" from hub "A", all the machines on hub "A"
> are happy.  Throughput is wonderful.  Introducing either the sun3 OR hub "B"
> into hub "A" trashes the throughput on hub "A".  I've tested this extensively.
> Even if the sun4 isn't connected to hub "B", connecting "B" to "A" trashes
> "A".  Doesn't make much sense, does it...

This remember me a stupid thing I did some time ago: by mistake I connected
something to both "uplink" and port 1 of a hub. But on this one "uplink" and
port 1 are the same thing, "uplink" is just a crossed plug.
This generated tons of errors and collistions on this hub.

Could it be something like this ?

--
Manuel Bouyer, LIP6, Universite Paris VI.           Manuel.Bouyer@lip6.fr
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