From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: Re: [RFC v2 2/4] net: enables interface option to skip IP Date: Tue, 25 Feb 2014 15:07:00 -0600 Message-ID: <1393362420.3032.8.camel__30927.1655082286$1393362447$gmane$org@dcbw.local> References: <1392857777.22693.14.camel@dcbw.local> <1393266120.8041.19.camel@dcbw.local> <20140224.180426.411052665068255886.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WIPC8-0008FJ-6B for xen-devel@lists.xenproject.org; Tue, 25 Feb 2014 21:05:40 +0000 In-Reply-To: <20140224.180426.411052665068255886.davem@davemloft.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: David Miller Cc: kvm@vger.kernel.org, mcgrof@do-not-panic.com, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jmorris@namei.org, zoltan.kiss@citrix.com, kuznet@ms2.inr.ac.ru, xen-devel@lists.xenproject.org, kaber@trash.net List-Id: xen-devel@lists.xenproject.org On Mon, 2014-02-24 at 18:04 -0500, David Miller wrote: > From: Dan Williams > Date: Mon, 24 Feb 2014 12:22:00 -0600 > > > In the future I expect more people will want to disable IPv4 as > > they move to IPv6. > > I definitely don't. > > I've been lightly following this conversation and I have to say > a few things. > > disable_ipv6 was added because people wanted to make sure their > machines didn't generate any ipv6 traffic because "ipv6 is not > mature", "we don't have our firewalls configured to handle that > kind of traffic" etc. > > None of these things apply to ipv4. > > And if you think people will go to ipv6 only, you are dreaming. > > Name a provider of a major web sitewho will go to strictly only > providing an ipv6 facing site? > > Only an idiot who wanted to lose significiant nunbers of page views > and traffic would do that, so ipv4 based connectivity will be > universally necessary forever. > > I think disable_ipv4 is absolutely a non-starter. Also, disable_ipv4 signals *intent*, which is distinct from current state. Does an interface without an IPv4 address mean that the user wished it not to have one? Or does it mean that DHCP hasn't started yet (but is supposed to), or failed, or something hasn't gotten around to assigning an address yet? disable_ipv4 lets you distinguish between these two cases, the same way disable_ipv6 does. Dan