From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934764AbcIUQMk (ORCPT ); Wed, 21 Sep 2016 12:12:40 -0400 Received: from charlotte.tuxdriver.com ([70.61.120.58]:58581 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933316AbcIUQMg (ORCPT ); Wed, 21 Sep 2016 12:12:36 -0400 Date: Wed, 21 Sep 2016 12:12:12 -0400 From: Neil Horman To: David Laight Cc: Sun Paul , "linux-sctp@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: Address already in use problem Message-ID: <20160921161211.GC13620@hmsreliant.think-freely.org> References: <20160921154304.GB13620@hmsreliant.think-freely.org> <063D6719AE5E284EB5DD2968C1650D6DB010623F@AcuExch.aculab.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6DB010623F@AcuExch.aculab.com> User-Agent: Mutt/1.7.0 (2016-08-17) X-Spam-Score: -2.9 (--) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 21, 2016 at 03:56:41PM +0000, David Laight wrote: > From: Neil Horman > > Sent: 21 September 2016 16:43 > > On Wed, Sep 21, 2016 at 09:44:30PM +0800, Sun Paul wrote: > > > Hi > > > > > > we have an SCTP application running in JAVA. and we found that there > > > is a problem when we as a client trying to connect to a remote IP > > > address. > > > > > > If the remote IP address is not accessible, our application will keep > > > retrying to connect using a self-defined local port address, says > > > 51001, > > > > > > We found that after sometimes, says 2 hrs, this port 51001 is never > > > able to bind to us again. even we tried to restart the application. > > > > > Sounds like you have another application that inadvertently bound to that port. > > Its not a privlidged port, nor is it well known, so it seems plausible that > > another application would eventually bind to it. Thats not a bug, just the way > > ip works. > > > > run netstat -anp | grep 51001 > > > > And see what application is holding the port. > > Not much chance of a distro having a netstat that gives sctp info. > You might find something in /proc/net/sctp. > True, but there is also no guarantee that the other application that claimed the port in question is using SCTP. Neil > 3.18 contains a fix for a problem with shutdown() being called > after the remote sends an INIT to restart an active connection > when there is unacked data. > If that happens the socket isn't released ever. > > A workaround is to use SO_LINGER to get the connection aborted. > > David > >