From owner-freebsd-ipfw Wed Jul 17 10:49:24 2002 Delivered-To: freebsd-ipfw@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 38F3537B400 for ; Wed, 17 Jul 2002 10:49:22 -0700 (PDT) Received: from sccrmhc02.attbi.com (sccrmhc02.attbi.com [204.127.202.62]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3AC7E43E42 for ; Wed, 17 Jul 2002 10:49:21 -0700 (PDT) (envelope-from crist.clark@attbi.com) Received: from blossom.cjclark.org ([12.234.91.48]) by sccrmhc02.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020717174920.KASL6023.sccrmhc02.attbi.com@blossom.cjclark.org>; Wed, 17 Jul 2002 17:49:20 +0000 Received: from blossom.cjclark.org (localhost. [127.0.0.1]) by blossom.cjclark.org (8.12.3/8.12.3) with ESMTP id g6HHnKJK025843; Wed, 17 Jul 2002 10:49:20 -0700 (PDT) (envelope-from crist.clark@attbi.com) Received: (from cjc@localhost) by blossom.cjclark.org (8.12.3/8.12.3/Submit) id g6HHnJAu025842; Wed, 17 Jul 2002 10:49:19 -0700 (PDT) X-Authentication-Warning: blossom.cjclark.org: cjc set sender to crist.clark@attbi.com using -f Date: Wed, 17 Jul 2002 10:49:19 -0700 From: "Crist J. Clark" To: Luigi Rizzo Cc: ipfw@FreeBSD.ORG Subject: Re: Ouch! ipfw log and DoS Message-ID: <20020717174919.GB25404@blossom.cjclark.org> Reply-To: "Crist J. Clark" References: <20020716124059.A2635@iguana.icir.org> <20020717064647.GC22967@blossom.cjclark.org> <20020717022619.A8351@iguana.icir.org> <20020717165807.GA25404@blossom.cjclark.org> <20020717102119.A12639@iguana.icir.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020717102119.A12639@iguana.icir.org> User-Agent: Mutt/1.4i 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 Wed, Jul 17, 2002 at 10:21:19AM -0700, Luigi Rizzo wrote: > On Wed, Jul 17, 2002 at 09:58:08AM -0700, Crist J. Clark wrote: > ... > > I just really do not think that this is the right place for such a > > limit. I don't like the idea that the firewall code just starts > > dropping notifications without way to know about it. Think about what > > happens for your example, a packet comes in that gets logged which > > triggers a syslog cascade until we hit the limit. What we end up with > > is only logging a small windows separated by at least a second, and > > the logs are still almost entirely filled with the syslog feedback. > > the alternative being having your box hung until you hard-reset it, > i know what i would choose :) There's still IPFIREWALL_VERBOSE_LIMIT and 'logamount' to save you from such a fate. If you disable log limiting AND misconfigure your rules to create feedback loops, I would have no sympathy for you. (Does the kernel really spend enough time generating messages that you get a real hang (the console hangs, not just remote sessions)?) -- 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