From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH 3/7 net-2.6.25] [IPV4]: Prohibit assignment of 0.0.0.0 as interface address. Date: Fri, 25 Jan 2008 15:01:34 +0100 Message-ID: <4799EBBE.6080706@fr.ibm.com> References: <1201269123-20378-1-git-send-email-den@openvz.org> <1201269123-20378-3-git-send-email-den@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org, devel@openvz.org, containers@lists.osdl.org To: "Denis V. Lunev" Return-path: Received: from mtagate4.de.ibm.com ([195.212.29.153]:10578 "EHLO mtagate4.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755951AbYAYOEt (ORCPT ); Fri, 25 Jan 2008 09:04:49 -0500 Received: from d12nrmr1607.megacenter.de.ibm.com (d12nrmr1607.megacenter.de.ibm.com [9.149.167.49]) by mtagate4.de.ibm.com (8.13.8/8.13.8) with ESMTP id m0PE4mjm034392 for ; Fri, 25 Jan 2008 14:04:48 GMT Received: from d12av03.megacenter.de.ibm.com (d12av03.megacenter.de.ibm.com [9.149.165.213]) by d12nrmr1607.megacenter.de.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m0PE4mwo1138856 for ; Fri, 25 Jan 2008 15:04:48 +0100 Received: from d12av03.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av03.megacenter.de.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m0PE4mt8023399 for ; Fri, 25 Jan 2008 15:04:48 +0100 In-Reply-To: <1201269123-20378-3-git-send-email-den@openvz.org> Sender: netdev-owner@vger.kernel.org List-ID: Denis V. Lunev wrote: > I could hardly imagine why sombady needs to assign 0.0.0.0 as an interface > address or interface destination address. The kernel will behave in a strage > way in several places if this is possible, as ifa_local != 0 is considered > as initialized/non-initialized state of the ifa. AFAICS, we should be able to set at an interface address to 0.0.0.0, in order to remove an IP address from an interface and keep this one up. I see two trivial cases: * remove the ipv4 on an interface but continue to use it through ipv6 * move ipv4 address from the interface to an attached bridge