From owner-freebsd-security Tue Jun 26 12:30:49 2001 Delivered-To: freebsd-security@freebsd.org Received: from db.nexgen.com (db.nexgen.com [64.81.208.78]) by hub.freebsd.org (Postfix) with SMTP id 5213737B405 for ; Tue, 26 Jun 2001 12:30:43 -0700 (PDT) (envelope-from ml@db.nexgen.com) Received: (qmail 76132 invoked from network); 26 Jun 2001 19:31:06 -0000 Received: from localhost.nexgen.com (HELO book) (root@127.0.0.1) by localhost.nexgen.com with SMTP; 26 Jun 2001 19:31:06 -0000 Message-ID: <002701c0fe76$7530eab0$01000001@book> From: "alexus" To: "Peter Pentchev" Cc: "Simon Rakovec" , References: <006a01c0fb6b$2d64d830$9865fea9@book> <3B36267B.5B5FDBE@inforta.com> <20010625093731.A934@ringworld.oblivion.bg> <01ec01c0fdb1$6c9cada0$9865fea9@book> <20010626085804.E780@ringworld.oblivion.bg> Subject: Re: disable traceroute to my host Date: Tue, 26 Jun 2001 15:30:28 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org someone else using ttl=1? that's sux.. oh well i guess its imposible to disable it.. cuz i dont want to block something that should work.. thanks everyone ----- Original Message ----- From: "Peter Pentchev" To: "alexus" Cc: "Simon Rakovec" ; Sent: Tuesday, June 26, 2001 1:58 AM Subject: Re: disable traceroute to my host > On Mon, Jun 25, 2001 at 04:00:03PM -0400, alexus wrote: > > i agree this is not a solution.. looks like tty=1 is best solution so far > > TTL=1 is not a general solution, because it only blocks traceroutes to this > particular host, not to any machines that it is acting as a gateway for. > > Moreover, TTL=1 is not a real-world solution, because some *legitimate* > packets might arrive with TTL=1 (yes, there are some OS's that set too > low TTL's on outgoing packets, and there are some global backbone ISP's > which have a *lot* of routers, so it is possible that a normal packet > destined for your host should reach you with TTL=1). > > And just btw.. Really, why do you want to block traceroutes? > > G'luck, > Peter > > -- > because I didn't think of a good beginning of it. > > > ----- Original Message ----- > > From: "Peter Pentchev" > > To: "Simon Rakovec" > > Cc: > > Sent: Monday, June 25, 2001 2:37 AM > > Subject: Re: disable traceroute to my host > > > > > > > On Sun, Jun 24, 2001 at 07:42:19PM +0200, Simon Rakovec wrote: > > > > Try this: > > > > > > > > ipfw add deny udp from any 32769-65535 to 33434-33523 > > > > > > As Karsten noted in a followup, this is not proper network practice. > > > There might be a LOT of things listening on those UDP ports, including > > > ephemeral outgoing UDP connections. > > > > > > As many other people noted, this does not stop Windows traceroute, > > > which goes via ICMP. > > > > > > As the traceroute(8) manpage notes, this does not stop people who > > > know how to use the traceroute '-p port' option to select a starting > > > port != 32768. > > > > > > As Dag-Erling Smoerdgrav noted, in general it is impossible to disable > > > a person determined to traceroute you, and in practice, there is > > > no need to. > > > > > > G'luck, > > > Peter > > > > > > PS. How was that now... one source: plagiarism, two sources: comparative > > > study, three sources: an academic thesis.. I did even better than that! > > ;) > > > > > > -- > > > Thit sentence is not self-referential because "thit" is not a word. > > > > > > > alexus wrote: > > > > > > > > > > is it possible to disable using ipfw so people won't be able to > > traceroute > > > > > me? > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message