From owner-freebsd-mobile@FreeBSD.ORG Wed Apr 16 11:01:43 2003 Return-Path: Delivered-To: freebsd-mobile@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8D32437B401 for ; Wed, 16 Apr 2003 11:01:43 -0700 (PDT) Received: from lerami.lerctr.org (lerami.lerctr.org [207.158.72.11]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7128F43FA3 for ; Wed, 16 Apr 2003 11:01:42 -0700 (PDT) (envelope-from ler@lerctr.org) Received: from lerlaptop.iadfw.net (lerlaptop.iadfw.net [206.66.13.21]) (authenticated bits=0)h3GI1c3R018000; Wed, 16 Apr 2003 13:01:39 -0500 (CDT) Date: Wed, 16 Apr 2003 13:01:38 -0500 From: Larry Rosenman To: John Polstra , mobile@freebsd.org Message-ID: <290420000.1050516098@lerlaptop.iadfw.net> In-Reply-To: <200304161758.h3GHwK8Y080748@strings.polstra.com> References: <20030416105033.H46401-100000@moo.sysabend.org> <200304161758.h3GHwK8Y080748@strings.polstra.com> X-Mailer: Mulberry/3.0.3 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Virus-Scanned: by amavisd-milter (http://amavis.org/) Subject: Re: "broadcast ping" message X-BeenThere: freebsd-mobile@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Mobile computing with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Apr 2003 18:01:43 -0000 --On Wednesday, April 16, 2003 10:58:20 -0700 John Polstra wrote: > In article <20030416105033.H46401-100000@moo.sysabend.org>, > Jamie Bowden wrote: >> On Wed, 16 Apr 2003, John Polstra wrote: >> >> > To make a FreeBSD system respond to broadcast pings, you have to set >> > the sysctl variable net.inet.icmp.bmcastecho to 1. >> >> Shouldn't the default be to DTRT and respond unless disabled? Until now, >> the only systems on my network that didn't respond to broadcast pings >> were my windows boxes, but I consider them broken by default. Why has >> the default behavior changed, and isn't this a POLA issue? > > It was changed for security reasons. Responding to broadcast pings > creates several potential denial of service attacks. It's also against current best practices for ISP's. Even Cisco changed the routers to NOT respond to directed-broadcast by default. The RFC was NOT written for today's internet. Larry Rosenman Sr. Network Engineer Dallas, TX -- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 972-414-9812 E-Mail: ler@lerctr.org US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749