From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stas Sergeev Subject: Re: Q: bad routing table cache entries Date: Tue, 29 Dec 2015 18:38:00 +0300 Message-ID: <5682A8D8.5040403@list.ru> References: <5682665A.7090102@list.ru> <20151229152208.GA22423@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev To: Sowmini Varadhan Return-path: Received: from smtp48.i.mail.ru ([94.100.177.108]:57718 "EHLO smtp48.i.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753239AbbL2PiH (ORCPT ); Tue, 29 Dec 2015 10:38:07 -0500 In-Reply-To: <20151229152208.GA22423@oracle.com> Sender: netdev-owner@vger.kernel.org List-ID: 29.12.2015 18:22, Sowmini Varadhan =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > Do you have admin control over the ubuntu router? > If yes, you might want to check the shared_media [#] setting=20 > on that router for the interfaces with overlapping subnets. > (it is on by default, I would try turning it off). Ahha, good catch, thanks! Done that, then ip route flush cache on host, and am waiting for the problem to re-appear. Hope it won't... but to say for sure I'll need a day or 2, as it is not very fast to appear. > AFAICT, the code does the right thing per rfc1812 when setting > IPSKB_DOREDIRECT if shared_media is turned off. Likely the router's side is doing the right thing, but of course there are still many questions about the host's side. Namely, why the bad entries were allowed, and how to list them? The problem would not happen if they are rejected based on a simple netmask check. Thanks for your help so far! With shared_media hint you've pretty likely saved me from lots of headache. :)