From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: Support for ICMP Time Exceeded in REJECT target ? Date: Thu, 10 Jan 2008 10:23:30 +0100 Message-ID: <200801101023.35077.laurentp@cse-semaphore.com> References: <200801091818.38810.laurentp@cse-semaphore.com> <4785D984.9000909@freemail.hu> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2308161.DyyLLvkysN"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4785D984.9000909@freemail.hu> Sender: netfilter-owner@vger.kernel.org List-ID: To: =?iso-8859-1?q?G=E1sp=E1r_Lajos?= Cc: netfilter@vger.kernel.org --nextPart2308161.DyyLLvkysN Content-Type: text/plain; charset="iso-8859-2" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Thursday 10 January 2008 09:38, G=E1sp=E1r Lajos wrote: > Laurent Pinchart =EDrta: > > ... > > > I know that my application breaks the OSI model and creates some kind of > > hybrid "layer 2.5" device. I'm open to suggestions regarding a better w= ay > > to implement bridges enumeration between two ethernet hosts, but using > > the traceroute command is a customer requirement which could only be > > changed with strong valid reasons. > > I'm really curios why would anyone need to enumerate the bridging host? > Could you explain? Our customer needs IP connectivity between two computers in the engines at= =20 each end of the train. Each carriage will have an embedded routing device,= =20 and connecting the carriages together creates a chain that ensures IP=20 connectivity. The customer's application requires enumerating the carriages. One easy=20 solution was to enumerate the routing devices in the chain, either using=20 their MAC or IP address. Configuring the devices as layer 3 routers would b= e=20 really complex, as all routing tables must be automatically updated wheneve= r=20 a carriage is added or removed. Using layer 2 bridges is much easier, but w= e=20 then loose layer 3 route tracing. This is why we thought about making some= =20 kind of hybrid device that acts as a layer 2 bridge except that it decremen= ts=20 the IP TTL and sends an ICMP Time Exceeded message when the TTL reaches 0. Best regards, =2D-=20 Laurent Pinchart CSE Semaphore Belgium Chauss=E9e de Bruxelles, 732A B-1410 Waterloo Belgium T +32 (2) 387 42 59 =46 +32 (2) 387 42 75 --nextPart2308161.DyyLLvkysN Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) iD8DBQBHheQX8y9gWxC9vpcRApBhAKCMM+M/oVDFQ4aZsrlTav9WLDqpmQCePbvl GKg3PjUf6fkwsaif0/bjSog= =vGJO -----END PGP SIGNATURE----- --nextPart2308161.DyyLLvkysN--