Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 23 Dec 2000 20:09:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 23 Dec 2000 20:09:08 -0500 Received: from itaipu.nitnet.com.br ([200.255.111.241]:56850 "HELO itaipu.nitnet.com.br") by vger.kernel.org with SMTP id ; Sat, 23 Dec 2000 20:08:51 -0500 Date: Sat, 23 Dec 2000 22:38:14 -0200 To: David Schwartz Cc: linux-kernel@vger.kernel.org Subject: Re: TCP keepalive seems to send to only one port Message-ID: <20001223223814.A2281@flower.cesarb> In-Reply-To: <20001223213156.A1947@flower.cesarb> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from davids@webmaster.com on Sat, Dec 23, 2000 at 04:19:31PM -0800 From: Cesar Eduardo Barros Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 23, 2000 at 04:19:31PM -0800, David Schwartz wrote: > > > This means that keepalive is useless for keeping alive more than > > one connection > > to a given host. > > Actually, keepalive is useless for keeping connections alive anyway. It's > very badly named. It's purpose is to detect dead peers, not keep peers > alive. Then what do you do when you are behind a NAT? And how do you expire entries in ESTABLISHED state that could stay lingering forever without some sort of keepalive? (The FINs might have been lost due to a conectivity transient, so you can have another perfectly valid and alive connection with the same host, and application-level timeouts are useless for some applications (*cough*nc*cough*)) -- Cesar Eduardo Barros cesarb@nitnet.com.br cesarb@dcc.ufrj.br - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/