From: Sorin Manolache <sorinm@gmail.com>
To: Guillaume Nault <g.nault@alphalink.fr>
Cc: netdev@vger.kernel.org, Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: Fw: [Bug 111771] New: deadlock in ppp/l2tp
Date: Thu, 4 Feb 2016 02:32:48 +0100 [thread overview]
Message-ID: <56B2AA40.5090601@gmail.com> (raw)
In-Reply-To: <20160203171401.GC1267@alphalink.fr>
On 2016-02-03 18:14, Guillaume Nault wrote:
> On Wed, Feb 03, 2016 at 11:04:31AM +1100, Stephen Hemminger wrote:
>> Please excuse URL mangling, my bugzilla address appears to route through
>> stupid corporate firewall.
>>
>
> Sorin, it seems like one of your L2TP tunnels is routed to one of its upper PPP
> devices. Most likely, the peer address of the PPP device is also the address of
> the remote L2TP tunnel endpoint. So L2TP packets are sent back to the upper PPP
> device, instead of leaving through the physical interface.
Thank you. You are right. There's a host route to the peer over the ppp0
interface in the routing table. I don't know how it gets there. I've
checked the source code of pppd and no such route is added for kernels
newer than 2.1.16. I've grepped /etc for "route" in order to detect a
"post-up" script that would add that route. Nothing. I've double-checked
by executing strace on xl2tpd and its children (i.e. pppd and the
initialisation scripts) and I couldn't find any ioctl SIOCADDRT. So it's
a total mystery for me where that route comes from. Could it come from
the kernel?
I've found this 9-year-old bug report:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=444180. I've adopted
the strategy that the comment proposes: delete the route in an post-up
script.
Thanks again.
Best regards,
Sorin
next prev parent reply other threads:[~2016-02-04 1:32 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 0:04 Fw: [Bug 111771] New: deadlock in ppp/l2tp Stephen Hemminger
2016-02-03 17:14 ` Guillaume Nault
2016-02-04 1:32 ` Sorin Manolache [this message]
2016-02-04 13:05 ` Guillaume Nault
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