From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: icmp_unreachable uses wrong ip Date: Tue, 03 May 2005 00:04:48 +0200 Message-ID: <4276A400.2050306@trash.net> References: <1115040079.5620.11.camel@jeroens.office.netland.nl> <200505021659.05674.hasso@estpak.ee> <42763E96.1070209@trash.net> <200505022038.22014.hasso@estpak.ee> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: "J. Simonetti" , netdev@oss.sgi.com Return-path: To: Hasso Tepper In-Reply-To: <200505022038.22014.hasso@estpak.ee> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Hasso Tepper wrote: > Patrick McHardy wrote: >=20 >>Why can't you simply add the prefered source address to the route? >=20 > Because I don't know what it is. Router A knows what's the best path fr= om=20 > router A to router B, but he can't know (at least in cases where there = are=20 > more than 1 path between them) what's the best path from router B to ro= uter=20 > A. Therefore you can=E4t say which one is incoming interface in router = A for=20 > traffic from router B. And even if you know it in some moment, topology= =20 > might change in next moment (dynamic routing) etc. Your patch can't guarantee that the address used is the same that was used as nexthop by the previous hop in the path when multiple addresses are configured on the incoming interface. So I don't think it achieves much of your goal of making debugging complicated topologies easier. Regards Patrick