Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 13 Jul 1998 19:58:20 -0400 (EDT)
From:      Robert Watson <robert@cyrus.watson.org>
To:        Ludwig Pummer <ludwigp@bigfoot.com>
Cc:        Alexander Kandelaki <stealth@sanet.ge>, freebsd-security@FreeBSD.ORG
Subject:   Re: Question...
Message-ID:  <Pine.BSF.3.96.980713195634.8340D-100000@fledge.watson.org>
In-Reply-To: <3.0.3.32.19980713104816.03203d78@mail.plstn1.sfba.home.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 13 Jul 1998, Ludwig Pummer wrote:

> My guess is someone either a) has an incorrectly set firewall/proxy gateway
> system or b) is trying to hack/break your machine
> My guess is that it's b), since people who try to hack/break your machine
> try to hide who they are by spoofing their IP.

I have a number of machines attached to a private network with a reserved
address range in use -- I have ipfw set up to reject packets from that
address range coming from the exposed interfaces on the big bad internet.
I often see ipfw accounting entries from rejected packets that are
addressed to or from the reserved address range on the outside interfaces.
I've never caught any in a sniffer, but then, I have never tried.

I suggest everyone verify their ipfw/border router filters to make sure
they are rejecting appropriate ranges of addresses!

  Robert N Watson 

Carnegie Mellon University            http://www.cmu.edu/
TIS Labs at Network Associates, Inc.  http://www.tis.com/
SafePort Network Services             http://www.safeport.com/
robert@fledge.watson.org              http://www.watson.org/~robert/


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



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.3.96.980713195634.8340D-100000>