From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Fink Subject: Re: TCP timewait recycle/reuse for IPv6? Date: Tue, 18 Mar 2008 01:27:39 -0400 Message-ID: <20080318012739.6a5c8602.billfink@mindspring.com> References: <200803171818.17494.opurdila@ixiacom.com> <47DEADC1.1040908@hp.com> <200803172004.33246.opurdila@ixiacom.com> <20080317.121006.206760103.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: opurdila@ixiacom.com, rick.jones2@hp.com, netdev@vger.kernel.org To: David Miller Return-path: Received: from elasmtp-masked.atl.sa.earthlink.net ([209.86.89.68]:45448 "EHLO elasmtp-masked.atl.sa.earthlink.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756421AbYCRF1x (ORCPT ); Tue, 18 Mar 2008 01:27:53 -0400 In-Reply-To: <20080317.121006.206760103.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 17 Mar 2008, David Miller wrote: > From: Octavian Purdila > Date: Mon, 17 Mar 2008 20:04:33 +0200 > > > While running the same traffic with IPv4, the timewait recyle/reuse > > features kicks in and keeps the number of TIMEWAIT sockets to under > > a 1000. > > Timewait recycling should not be enabled if any of your connections > could even potentially be going through a firewall or NAT box. > In such cases, the invariants which are necessary for timewait > recycling to be valid are not present and thus you could risk > connection or data corruption. > > Timewait recycling depends upon end systems really being end > systems on a connection level. With NAT, that is no longer > true, as the NAT box will reuse the same port for different > end nodes in subsequent connections. I have this hope that as IPv6/IPSEC becomes more commonplace, perhaps it can help get back to the original TCP/IP direct end system to end system model of communication, and reduce the current need for such unfortunately necessary kludges as NAT boxes. -Bill