From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glen Turner Subject: Re: icmp_unreachable uses wrong ip Date: Wed, 04 May 2005 10:45:45 +0930 Message-ID: <42782241.6080909@aarnet.edu.au> References: <1115040079.5620.11.camel@jeroens.office.netland.nl> <20050503092244.GA8864@xi.wantstofly.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@oss.sgi.com Return-path: To: Pekka Savola In-Reply-To: Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Pekka Savola wrote: > > > There's no specification requiring or recommending either of these > approaches, either for v6 or v4 AFAICS so you can't depend on that > behaviour.. In the lack of a specification, doing what works best for network operators would be nice :-) And that behaviour is that addresses in a traceroute should be ping-able. That is, you're tracing the route and there's loss at one point, so you want to determine how much loss. The outgoing interface's address may not be reached down the same path as used by the traceroute, whereis the incoming address obviously is (or if it isn't, then that itself is interesting diagnostic information). Similarly, using the incoming interface gives more information about asymetric routes. In short, since using the incoming address gives more useful output and the specification is silent as to which address is allowable, using the incoming interface's address would be the most useful choice. Cheers, Glen -- Glen Turner Tel: (08) 8303 3936 or +61 8 8303 3936 Australia's Academic & Research Network www.aarnet.edu.au