From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Friesen Subject: Re: Bug? TCP shutdown behaviour when deleting local IP addresses Date: Fri, 19 Oct 2012 09:12:32 -0600 Message-ID: <50816DE0.4070700@genband.com> References: <507F38D4.102@genband.com> <1350540348.26103.1015.camel@edumazet-glaptop> <507FAAE1.6000903@genband.com> <1350545382.26103.1103.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev , David Miller , Alexey Kuznetsov , James Morris , Patrick McHardy , Hideaki YOSHIFUJI To: Eric Dumazet Return-path: Received: from exprod7og127.obsmtp.com ([64.18.2.210]:53521 "EHLO exprod7og127.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751259Ab2JSPNS (ORCPT ); Fri, 19 Oct 2012 11:13:18 -0400 In-Reply-To: <1350545382.26103.1103.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On 10/18/2012 01:29 AM, Eric Dumazet wrote: > On Thu, 2012-10-18 at 01:08 -0600, Chris Friesen wrote: > >> >> While I agree generally, it's a bit unfortunate that we can't (as a >> quality of implementation thing) give an earlier notice of failure since >> the kernel knows about both ends of the connection even though the IP >> address is gone. On the other hand, I imagine that would mean >> special-casing things and presumably that would open a whole can of worms. > > Really what is the difference between a cable cut and what you are > doing ? > > Some frames are lost (Dropped), and sender doesnt 'know' that is > definitive or temporary failure. > > If you want faster response, you need to send RST messages, not dropping > frames. After thinking about it for a while, I think you're right. Initially I was expecting that since we know the server side has been taken down we should be able to kill the client side, but then I considered the case where some sort of of high availability system may have moved the server to another host. > So change your strategy, and add an iptables rule for example ? That's a good suggestion. I'll pass it on. Thanks, Chris