Date: Tue, 22 Jun 1999 05:00:34 PDT From: N.N.M <madrapour@hotmail.com> To: mwlucas@exceptionet.com, madrapour@hotmail.com Cc: freebsd-security@FreeBSD.ORG Subject: Re: Question: Preventing Smurf Message-ID: <19990622120038.735.qmail@hotmail.com>
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Thanks for your reply. That is the point: I disable net.inet.icmp.bmcastecho (=0) on a freebsd box with the IP, i.e. x.x.11.18. But when I use broadcast ping (ping x.x.11.255) on another pc (i.e. x.x.11.17) on the same Ethernet, the first machine which is not supposed to reply to the ping, will reply! So I thought I might need another thing to disable that or maybe using broadcast ping on the same Ethernet isn't a good way to test it or ...... Any idea? Nazila M. >From: mwlucas@exceptionet.com >To: madrapour@hotmail.com (N.N.M) >CC: freebsd-security@FreeBSD.ORG >Subject: Re: Question: Preventing Smurf >Date: Tue, 22 Jun 1999 07:06:52 -0400 (EDT) >MIME-Version: 1.0 >From mwlucas@easeway.com Tue Jun 22 11:18:15 1999 >Received: (from mwlucas@localhost)by easeway.com (8.8.8/8.8.5) id >HAA02940;Tue, 22 Jun 1999 07:06:56 -0400 (EDT) >Message-Id: <199906221106.HAA02940@easeway.com> >In-Reply-To: <19990622073945.98174.qmail@hotmail.com> from "N.N.M" at "Jun >22, 99 00:39:43 am" >X-Mailer: ELM [version 2.4ME+ PL32 (25)] > >To test if it works, ping your subnet's broadcast address (i.e., >a.b.c.255). If you're not sure of the broadcast, an ifconfig -a will give >it to you. > >The machine won't respond to a broadcast ping. This will prevent you from >being a smurf relay. > >A more effective method would be to block broadcast pings at the router to >your network. Check your router's documentation or mfg. web site for >exact instructions. > >Regards, >==ml > > > > > > Hi, > > > > Is it enough to do "sysctl -w net.inet.icmp.bmcastecho=0" to prevent >being > > Smurf Intermediary? And if so, how can I check it to get sure if it is >ok? > > I did the above change, but my freebsd box still responses to ping (from >a > > pc on the same Ehternet) to broadcast address. Is it normal? > > > > thanks, > > Nazila M. > > > > > > ______________________________________________________ > > Get Your Private, Free Email at http://www.hotmail.com > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > with "unsubscribe freebsd-security" in the body of the message > > > > >-- >Michael Lucas | >Exceptionet, Inc. | www.exceptionet.com >"Exceptional Networking" | > ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message
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