From owner-freebsd-ipfw Thu Apr 25 23:24:50 2002 Delivered-To: freebsd-ipfw@freebsd.org Received: from rwcrmhc51.attbi.com (rwcrmhc51.attbi.com [204.127.198.38]) by hub.freebsd.org (Postfix) with ESMTP id E5F9C37B417; Thu, 25 Apr 2002 23:24:45 -0700 (PDT) Received: from blossom.cjclark.org ([12.234.91.48]) by rwcrmhc51.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020426062445.DRJD8969.rwcrmhc51.attbi.com@blossom.cjclark.org>; Fri, 26 Apr 2002 06:24:45 +0000 Received: (from cjc@localhost) by blossom.cjclark.org (8.11.6/8.11.6) id g3Q6OiA34698; Thu, 25 Apr 2002 23:24:44 -0700 (PDT) (envelope-from cjc) Date: Thu, 25 Apr 2002 23:24:44 -0700 From: "Crist J. Clark" To: Gregory Neil Shapiro Cc: "Rex A. Roof" , freebsd-ipfw@FreeBSD.ORG Subject: Re: Putting in place an incoming sendmail limit Message-ID: <20020425232444.B34367@blossom.cjclark.org> References: <200204252052.g3PKqrj0090391@gunjin.wccnet.org> <15560.29198.657946.738003@horsey.gshapiro.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <15560.29198.657946.738003@horsey.gshapiro.net>; from gshapiro@FreeBSD.ORG on Thu, Apr 25, 2002 at 02:15:58PM -0700 X-URL: http://people.freebsd.org/~cjc/ Sender: owner-freebsd-ipfw@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Thu, Apr 25, 2002 at 02:15:58PM -0700, Gregory Neil Shapiro wrote: > rex> In order to prevent incoming DoS attacks via multiple sendmail > rex> connections, I've tried adding the following ipfw rule: > > rex> allow tcp from any to any smtp limit src-addr 1 > > rex> This works great, except that when it's triggered I get A LOT > rex> of messages like this: > > rex> OUCH! cannot remove rule, count 1 > rex> drop session, too many entries > > Perhaps it is because that rule matches every packet into of just the TCP > setup packet. You might try using the 'setup' keyword. (Just a guess). That's probably not the problem. Remember 'limit' rules are dynamic rules. What version of FreeBSD are you running? I believe the 'OUCH!' is luigi's way of saying that you shouldn't be seeing that error. It indicates an internal error. -- Crist J. Clark | cjclark@alum.mit.edu | cjclark@jhu.edu http://people.freebsd.org/~cjc/ | cjc@freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-ipfw" in the body of the message