From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1767162AbXCILLW (ORCPT ); Fri, 9 Mar 2007 06:11:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1767172AbXCILLW (ORCPT ); Fri, 9 Mar 2007 06:11:22 -0500 Received: from z2.cat.iki.fi ([212.16.98.133]:42354 "EHLO z2.cat.iki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1767162AbXCILLV (ORCPT ); Fri, 9 Mar 2007 06:11:21 -0500 Date: Fri, 9 Mar 2007 13:11:20 +0200 From: Matti Aarnio To: Niklaus Cc: linux-kernel@vger.kernel.org Subject: Re: more than 65535 outbound connections Message-ID: <20070309111120.GE3883@mea-ext.zmailer.org> References: <85e0e3140703090016h609ecc5t504121a99bcd3e44@mail.gmail.com> <82d53izucg.fsf@mid.bfk.de> <85e0e3140703090243n36fd467dwc83aff0d7b6fb004@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <85e0e3140703090243n36fd467dwc83aff0d7b6fb004@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 09, 2007 at 04:13:00PM +0530, Niklaus wrote: > yes now lets take 2 dest machines , source ip is fixed , source port (2^16 > - 1) > destip is fixed (a.a.a.a and b.b.b.b) ,dest port(2^16 -1) each , > > for a connection we have one port used , say connection 1 is > > source ip,port 1 , a.a.a.a port 1 > source ip,port 2 , a.a.a.a port 2 > . > . > . > source ip,port 65535 , a.a.a.a port 65535 You do have some sort of fixation of having same port numbers at both ends. In some rare applications that is done (e.g. with NTP server-server connections using UDP), but it is very rare and never done with TCP. Now if you have 65535 server ports at a.a.a.a, you can have very nearly 4000 million TCP streams in between them. > so total of 65535 connections (assume traffic is still going on, a > movie on a slow line dialup or 1kbps ) > > now if i try to open another connection (assume lots of file > descriptors are present) to a.a.a.a what happens > > to b.b.b.b what happens > > i think both will not get established as the OS doesn't have any free > source ports or am i wrong you are wrong. > >David Lang /Matti Aarnio