From owner-freebsd-security  Thu Sep  9 12:32:55 1999
Delivered-To: freebsd-security@freebsd.org
Received: from verdi.nethelp.no (verdi.nethelp.no [158.36.41.162])
	by hub.freebsd.org (Postfix) with SMTP id C2C2E14C1D
	for <freebsd-security@FreeBSD.ORG>; Thu,  9 Sep 1999 12:32:51 -0700 (PDT)
	(envelope-from sthaug@nethelp.no)
Received: (qmail 13781 invoked by uid 1001); 9 Sep 1999 19:32:40 +0000 (GMT)
To: imp@village.org
Cc: jwyatt@rwsystems.net, Goran.Lowkrantz@infologigruppen.se,
	freebsd-security@FreeBSD.ORG
Subject: Re: Lisen only NIC 
From: sthaug@nethelp.no
In-Reply-To: Your message of "Thu, 09 Sep 1999 13:22:43 -0600"
References: <199909091922.NAA30860@harmony.village.org>
X-Mailer: Mew version 1.05+ on Emacs 19.34.2
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Date: Thu, 09 Sep 1999 21:32:40 +0200
Message-ID: <13779.936905560@verdi.nethelp.no>
Sender: owner-freebsd-security@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.org

> I've seen in other discussions that while you could do this with the
> AUI based ethernet cards, you can't do this with 10base2 or 10base-t
> cards.  Thinnet is obvious...  But the 10-base-t/100-base-t cards need
> the xmit lines to negotiate speed settings with the hub.  Can anybody
> confirm this?

Not just for the negotiation, but also to keep the link up. There are
link pulses sent at regular intervals. If these are not received, the
link is detected as being down.

It's possible to "cheat" on this with some active electronics. Anzen
makes a "receive only" cable, see

	http://www.anzen.com/afj/afj_faq.html#anchor157338

Disclaimer: I have no particular knowledge of the Anzen product, aside
from having seen a discussion about this on the NFR distribution list.

Steinar Haug, Nethelp consulting, sthaug@nethelp.no


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-security" in the body of the message