From owner-freebsd-net Wed Dec 19 9:58: 6 2001 Delivered-To: freebsd-net@freebsd.org Received: from whale.sunbay.crimea.ua (whale.sunbay.crimea.ua [212.110.138.65]) by hub.freebsd.org (Postfix) with ESMTP id 7436E37B419; Wed, 19 Dec 2001 09:57:47 -0800 (PST) Received: (from ru@localhost) by whale.sunbay.crimea.ua (8.11.6/8.11.2) id fBJHvK880565; Wed, 19 Dec 2001 19:57:20 +0200 (EET) (envelope-from ru) Date: Wed, 19 Dec 2001 19:57:20 +0200 From: Ruslan Ermilov To: Maxim Konovalov Cc: Yar Tikhiy , net@FreeBSD.ORG, hackers@FreeBSD.ORG Subject: Re: Processing IP options reveals IPSTEALH router Message-ID: <20011219195720.B72222@sunbay.com> References: <20011219194903.D21732@comp.chem.msu.su> <20011219195659.G25693-100000@news1.macomnet.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20011219195659.G25693-100000@news1.macomnet.ru> User-Agent: Mutt/1.3.23i Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Wed, Dec 19, 2001 at 08:54:50PM +0300, Maxim Konovalov wrote: > On 19:49+0300, Dec 19, 2001, Yar Tikhiy wrote: > > > On Wed, Dec 19, 2001 at 07:23:55PM +0300, Maxim Konovalov wrote: > > > > > > > I ran into an absolutely clear, but year-old PR pointing out that > > > > a router in the IPSTEALTH mode will reveal itself when processing > > > > IP options: kern/23123. > > > > > > > > The fix proposed seems clean and right to me: don't do IP options > > > > at all when in the IPSTEALTH mode. Does anyone have objections? > > > > If no, I'll commit the fix. > > > > > > First of all we should decide what IPSTEALTH is for. Is it just a > > > Ruslan's net.inet.ip.decttl or it should really stealth the fact of > > > the routing? If the latter how do we behave in source routing case? > > > > Are there any reasons for a router not to decrement IP TTL besides > > trying to stay invisible to a third party? > > imho there are not. I've asked because ru's net.inet.ip.decttl means > "do not decrement TTL" but not "hide the fact of the routing". > Nope, my net.inet.ip.decttl is the decrementor, it may be 1 (by default), 0 (to hide this router), or 2, 3, etc. Cheers, -- Ruslan Ermilov Oracle Developer/DBA, ru@sunbay.com Sunbay Software AG, ru@FreeBSD.org FreeBSD committer, +380.652.512.251 Simferopol, Ukraine http://www.FreeBSD.org The Power To Serve http://www.oracle.com Enabling The Information Age To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message