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From: Joe Greco <jgreco@brasil.moneng.mei.com>
Message-Id: <199611201716.LAA07479@brasil.moneng.mei.com>
Subject: Re: Ipx to ip routing
To: exidor@superior.net (Christopher Masto)
Date: Wed, 20 Nov 1996 11:16:31 -0600 (CST)
Cc: jgreco@brasil.moneng.mei.com, exidor@superior.net, hackers@freebsd.org
In-Reply-To: <199611201703.MAA11015@nimbus.superior.net> from "Christopher Masto" at Nov 20, 96 12:03:37 pm
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> The switches don't allow IP address collisions.  They associate a
> hardware address with an IP address and talk to each other to keep
> things in sync.  This is what they did where I went to school (RPI).
> When you're in your room with a laptop, packets for your IP get
> forwarded to that physical wire..  if you unplug the laptop and
> reconnect it in a classroom, the switch sees your first packet and
> updates its knowledge of where you are, physically.  If you try to use
> the wrong IP, you are only affecting the physical segment that you are
> on, because the switch knows it's not correct and probably even sends
> an SNMP trap to let the administrators know.

Ethernet switches are not supposed to do anything other than MAC level
address routing.

Switches by definition will certainly allow IP address collisions because
they do not have a clue what the hell an IP address is.

The other disadvantage of switches is the potentially large amount of
ARP'ing that can go on to locate hosts in such a network.

... JG