From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: IPV4: Enable IP_ID sequencing for all traffic (inquiring minds want to know why its set to zero) Date: Thu, 17 Jul 2008 18:12:53 +0200 Message-ID: <87r69ssd4q.fsf@basil.nowhere.org> References: <487E0C15.1070001@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: Christoph Lameter Return-path: Received: from smtp-out04.alice-dsl.net ([88.44.63.6]:40069 "EHLO smtp-out04.alice-dsl.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752574AbYGQQNz (ORCPT ); Thu, 17 Jul 2008 12:13:55 -0400 In-Reply-To: <487E0C15.1070001@linux-foundation.org> (Christoph Lameter's message of "Wed, 16 Jul 2008 09:56:21 -0500") Sender: netdev-owner@vger.kernel.org List-ID: Christoph Lameter writes: > There is some security reason why we set IP_ID == 0 right? Could someone point me at the discussions that lead to having IP_ID be zero? Have not been involved in network that much so forgive my ignorance.... and I can only find some hints about why this was done here and there using google. AFAIK it was just for efficiency. The way Linux generates ipids currently is somewhat expensive, because it aims to generate a per ip ipid counter, so it was turned off when not needed. I used to patch that out because it always seemed like overkill to me. -Andi