From owner-freebsd-security  Tue Jun 22  4:18:21 1999
Delivered-To: freebsd-security@freebsd.org
Received: from easeway.com (ns1.easeway.com [209.69.39.1])
	by hub.freebsd.org (Postfix) with ESMTP id 5278314E22
	for <freebsd-security@FreeBSD.ORG>; Tue, 22 Jun 1999 04:18:15 -0700 (PDT)
	(envelope-from mwlucas@easeway.com)
Received: (from mwlucas@localhost)
	by easeway.com (8.8.8/8.8.5) id HAA02940;
	Tue, 22 Jun 1999 07:06:56 -0400 (EDT)
Message-Id: <199906221106.HAA02940@easeway.com>
Subject: Re: Question: Preventing Smurf
In-Reply-To: <19990622073945.98174.qmail@hotmail.com> from "N.N.M" at "Jun 22, 99 00:39:43 am"
To: madrapour@hotmail.com (N.N.M)
Date: Tue, 22 Jun 1999 07:06:52 -0400 (EDT)
Cc: freebsd-security@FreeBSD.ORG
From: mwlucas@exceptionet.com
X-Mailer: ELM [version 2.4ME+ PL32 (25)]
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: owner-freebsd-security@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.org

To test if it works, ping your subnet's broadcast address (i.e.,
a.b.c.255).  If you're not sure of the broadcast, an ifconfig -a will give
it to you.

The machine won't respond to a broadcast ping.  This will prevent you from
being a smurf relay.

A more effective method would be to block broadcast pings at the router to
your network.  Check your router's documentation or mfg. web site for
exact instructions.

Regards,
==ml


> 
> Hi,
> 
> Is it enough to do "sysctl -w net.inet.icmp.bmcastecho=0" to prevent being
> Smurf Intermediary? And if so, how can I check it to get sure if it is ok?
> I did the above change, but my freebsd box still responses to ping (from a 
> pc on the same Ehternet) to broadcast address. Is it normal?
> 
> thanks,
> Nazila M.
> 
> 
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
> 
> 
> To Unsubscribe: send mail to majordomo@FreeBSD.org
> with "unsubscribe freebsd-security" in the body of the message
> 


-- 
Michael Lucas			|
Exceptionet, Inc.		|	www.exceptionet.com
"Exceptional Networking"	|


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