Date: Thu, 4 Oct 2012 10:58:16 -0700 From: John-Mark Gurney <jmg@funkthat.com> To: Dominic Blais <dblais@interplex.ca> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, "Alexander V. Chernikov" <melifaro@freebsd.org> Subject: Re: Default route destination changing without warning follow-up Message-ID: <20121004175816.GB1967@funkthat.com> In-Reply-To: <2DE61B0869B7484997BCA012845482C7EBE8E28133@WIN2008.Domnt.abi.ca> References: <2DE61B0869B7484997BCA012845482C7EBE8E280DB@WIN2008.Domnt.abi.ca> <5068AC17.8020704@FreeBSD.org> <2DE61B0869B7484997BCA012845482C7EBE8E280DC@WIN2008.Domnt.abi.ca> <5068ADCC.5030105@FreeBSD.org> <2DE61B0869B7484997BCA012845482C7EBE8E280DD@WIN2008.Domnt.abi.ca> <5068B48E.2070303@FreeBSD.org> <20121004160240.GA1967@funkthat.com> <2DE61B0869B7484997BCA012845482C7EBE8E28133@WIN2008.Domnt.abi.ca>
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Dominic Blais wrote this message on Thu, Oct 04, 2012 at 12:12 -0400: > There's never 2 default route... it's always a single default route. Since route monitor shows nothing, I guess it's the same route that gets its gateway changed for some reason... I guess the effective and appearing change could be due to a pointer changing somewhere or the memory space where is located the default gateway is replaced with new stuff... I don't know how it's coded but it looks like that kind of stuff since nothing is triggered on the route monitor radar... > > The default route always exists and there's no trace of it deleted prior to what my script does so we may be quite sure it's the same route that's brutalized ;) It looks like ddb does support breaking on a hardware address, so we might be able to track it down this way... If you can use ddb or gdb to track down the memory address of the ip of the default route, you can set an hwatch (see ddb(4)) on that address and hopefully catch the code that is corrupting the default route... I'm not familar w/ the routing system to help you figure out the address to watch on, etc... Maybe someone else can... Or you can try to read the code... Hope this helps... > Since mpd creates new interfaces for each new connection I see some route being added/replaced from time to time. I first thought it was mpd's fault because it was the only thing playing with routes but Krzysztof Barcikowski doesn't use MPD and shares the use of IPFW and PF like me and has the same default route gateway changing behaviour... > > > -- > > > > -----Message d'origine----- > De : John-Mark Gurney [mailto:jmg@funkthat.com] > Envoyé : 4 octobre 2012 12:03 > À : Alexander V. Chernikov > Cc : Dominic Blais; freebsd-net@freebsd.org > Objet : Re: Default route destination changing without warning follow-up > > Alexander V. Chernikov wrote this message on Mon, Oct 01, 2012 at 01:07 +0400: > > On 01.10.2012 00:59, Dominic Blais wrote: > > >It's all about IPv4 in my case. > > > > It will be great to supply some more details (e.g. like FreeBSD > > version, interfaces configuration, netstat -rn output). > > > > How often does this happen ? > > (e.g. while true; do echo -n `date` ; route -n get default | grep > > gate; sleep 1; done can help) > > > > If this is reproducible, what actions precedes this change? > > Maybe some ARP traffic on that interface, or interface > > creation/deletion, or.. ? > > > > Is route monitor completely silent when the change happens? > > Just for refernece, Dominic brought this up in an earlier thread: > http://www.freebsd.org/cgi/mid.cgi?2DE61B0869B7484997BCA012845482C7EBE62DDD88@WIN2008.Domnt.abi.ca > > and at least on other person seems to have the same issue... > > quick question for you Dominic, do you see the correct number of routes, but a new wrong one appear? or does the route just simply disapear? or does a new one seem to replace the old one? > > The reason I ask is that if a new wrong one appears, it could be memory corruption, but if a new one replaces the old one, for some reason when allocating a new route, it could accidentatlly be replacing the default route... > > Just some thoughts... -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."
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