From owner-freebsd-questions Wed Feb 9 11:14:29 2000 Delivered-To: freebsd-questions@freebsd.org Received: from wondermutt.net (host75-157.student.udel.edu [128.175.75.157]) by builder.freebsd.org (Postfix) with ESMTP id DD6A94148 for ; Wed, 9 Feb 2000 11:14:17 -0800 (PST) Received: from morgaine (morgaine.wondermutt.net [192.168.1.2]) by wondermutt.net (8.9.3/8.9.3) with SMTP id OAA57219; Wed, 9 Feb 2000 14:16:18 -0500 (EST) (envelope-from papalia@udel.edu) Message-Id: <4.1.20000209140745.009d5810@mail.udel.edu> X-Sender: papalia@mail.udel.edu X-Mailer: QUALCOMM Windows Eudora Pro Version 4.1 Date: Wed, 09 Feb 2000 14:10:55 -0500 To: Alfred Perlstein From: John Subject: Re: ICMP_BANDLIM Cc: freebsd-questions@FreeBSD.ORG In-Reply-To: <20000209112923.Y17536@fw.wintelcom.net> References: <4.1.20000209133845.0094c1c0@mail.udel.edu> <4.1.20000209133845.0094c1c0@mail.udel.edu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >> Hey all... >> >> With all the attacks going on on yahoo, ebay, etrade, etc, it reminded of a >> question I had a while back but forgot to ask... >> >> What exactly does the "ICMP_BANDLIM" kernel option do to provide >> 'protection'? Not much in the LINT file on it, and I can't search, so I >> thought I'd ask :) > >It restricts the amount of responces you will send in responce to bad >packets. > >If someone is sending you 100mbit of grabage down your pipe, you don't >want to overload the system and connection by forcing it to respond >to each and every packet. So, in other words, it's pretty much a choke you put on your reponse (ex: answer only 1 in every 1,000 ping requests you get from a particular IP ?). If so, are there dynamic settings to it? Or is just a single kernel option with no settings? And I'm also assuming that ICMP_BANDLIM is also a stopper for ALL network traffic (overload), not just particular items? Thanks again... I appreciate the time you took for an explanation =) --John To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message