From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: How I can reset TCP sockets after long suspend/resume cyscle Date: Wed, 04 Jun 2008 14:02:36 -0700 Message-ID: <484702EC.30209@hp.com> References: <200806011515.14103.maximlevitsky@gmail.com> <4846B5F2.8090805@gmail.com> <396556a20806040909q7e5eb8abi7cbc8b5ed11ed54e@mail.gmail.com> <20080604092154.7511c9d3@extreme> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Adam Langley , Maxim Levitsky , netdev@vger.kernel.org To: Stephen Hemminger Return-path: Received: from g4t0017.houston.hp.com ([15.201.24.20]:16512 "EHLO g4t0017.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752792AbYFDVCj (ORCPT ); Wed, 4 Jun 2008 17:02:39 -0400 In-Reply-To: <20080604092154.7511c9d3@extreme> Sender: netdev-owner@vger.kernel.org List-ID: While I know of at least one OS/stack which allows a root user to issue a command to abort a TCP connection, (and it may be two given their shared history) its use was always strongly discouraged. > TCP should recover from this anyway. As soon as any activity happens > on the connection the other end will respond with reset. For an IMAP > session doing the next get-mail should cause a connection reset. > Now it is possible that mail client has other problems. And one way for there to be activity would be for the application(s) in question to have an application-layer keepalive mechanism, or at the very least, set SO_KEEPALIVE on their connections. And if they don't want to rely on the sysadmin to have set what they consider a "reasonable" value for when to start sending keepalive probes, a TCP_KEEPIDLE setsockopt() perhaps. rick jones