From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: "ip neigh show" not showing arp cache entries? Date: Tue, 18 Dec 2007 01:35:39 +0100 Message-ID: <476715DB.6050808@trash.net> References: <4760279E.1080203@nortel.com> <47602DD0.8070402@cosmosbay.com> <47605934.2060604@nortel.com> <20071213.070641.20411400.yoshfuji@linux-ipv6.org> <476696A5.1010101@nortel.com> <4766B99D.8060408@trash.net> <4766D261.1020005@nortel.com> <47670B88.4010906@trash.net> <20071218003312.GR11220@postel.suug.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: Chris Friesen , yoshfuji@linux-ipv6.org, dada1@cosmosbay.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Thomas Graf Return-path: Received: from stinky.trash.net ([213.144.137.162]:40052 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761024AbXLRAfl (ORCPT ); Mon, 17 Dec 2007 19:35:41 -0500 In-Reply-To: <20071218003312.GR11220@postel.suug.ch> Sender: netdev-owner@vger.kernel.org List-ID: Thomas Graf wrote: > * Patrick McHardy 2007-12-18 00:51 >> Chris Friesen wrote: >>> Patrick McHardy wrote: >>> >>>> From a kernel perspective there are only complete dumps, the >>>> filtering is done by iproute. So the fact that it shows them >>>> when querying specifically implies there is a bug in the >>>> iproute neighbour filter. Does it work if you omit "all" >>> >from the ip neigh show command? >>> >>> Omitting "all" gives identical results. It is still missing entries >>> when compared with the output of "arp". >> >> In that case the easiest way to debug this is probably if you >> add some debugging to ip/ipneigh.c:print_neigh() since I'm >> unable to reproduce this problem. A printf for all the filter >> conditions (=> return 0) at the top should do. > > Alternatively, you can download libnl and run > > NLCB=debug src/nl-neigh-dump brief > > and check if the netlink message is sent by the kenrel for the > neighbour in question. It should be, according to Chris, "ip neigh show " does show the missing entries, and in case of neighbour entries all filtering is done in userspace.