Subject: Re: The impossible has happened.
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: David Gilbert <dgilbert@jaywon.pci.on.ca>
List: port-sparc
Date: 03/12/1996 23:20:47
>>>>> "Jason" == Jason Thorpe <thorpej@nas.nasa.gov> writes:

	[about two ethernets with the same address]

Jason> This isn't impossible!  On a Sun, this is a *feature*!  :-)

	Ah.  That's what they call it.

Jason> Not at all.  This is expected on a Sun system.  Note that on a
Jason> Sun, the MAC address isn't stored on a PROM on the card, but
Jason> rather on a PROM on the *motherboard*.  (This comes from the
Jason> idprom.)

[...]

Jason> For the record, this *really* breaks a dually-homed Sun that
Jason> has both interfaces on the same subnet.  Is this what's
Jason> happening in your case?

	If you're talking about my recent message about my DMA
underrun messages (this is happening to the detriment of actual
traffic on my little net), then no.  I have taken the second card out
of the machine --- it was just one of my attempts to get things
working.

	Now, the configuration is:  My Sun4/260 with it's stock
ethernet and a 386 with a 3c509 configured to use the AUI.  A DEC
'Delni' (8 port AUI concentrator) is connecting the two.  It's a
pretty simple network.

	From either machine, I can ping -f the other.  I seem to get
about 1 underrun every couple of seconds, then.  If I do a ping -f
from both at once, I get about 1 every second.

	Regardless, when I try to ftp with the 386 (it's not fully
installed yet so I can't ftp to it), I get lots of DMA underruns, and
am unable to do a dir or a get with it.

	I'm wondering if this is due to the small isolated nature of
my network here.

	The kernel on the Sun is a recent (after nfs upgrade) sup.  It
also happens with my older kernel (about 2-3 weeks before nfs).  The
kernel on the 386 is the 'other' boot disk kernel.  I have not been
able to transfer the new one yet.

Dave.

-- 
----------------------------------------------------------------------------
|David Gilbert, PCI, Richmond Hill, Ontario.  | Two things can only be     |
|Mail:      dgilbert@jaywon.pci.on.ca         |  equal if and only if they |
|http://www.pci.on.ca/~dgilbert               |   are precisely opposite.  |
---------------------------------------------------------GLO----------------