From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 2348A1381F3 for ; Mon, 5 Aug 2013 17:31:34 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 7EB7DE0B6E; Mon, 5 Aug 2013 17:31:24 +0000 (UTC) Received: from mail-ee0-f47.google.com (mail-ee0-f47.google.com [74.125.83.47]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 515D5E0AFC for ; Mon, 5 Aug 2013 17:31:23 +0000 (UTC) Received: by mail-ee0-f47.google.com with SMTP id d49so1727113eek.20 for ; Mon, 05 Aug 2013 10:31:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=Plks1MDUp6NW/2gtt9BOwjCdTegQkL7gmjCEVtFXdYo=; b=E0nCXgyuh24UBDS6R8CEZy1ursIE+tgHYSD0wPlEAjliBqNg+Vv//yrfNhiW8mZ986 qiOaudxZST60etOBFEKWSjMdfZIkvQdKsY7ihzylEH8mfhZJh3Jj/CZHDy7GhFe8Nn+f VfG4ZyD5wP1ERE2QU99Aci6nmS83h6GzJAS6KUYxGYAVc6FHepcKhCdn2ltVSYOYgn3R b1ROIgs/NFYJGkLsS0JnOq3MMGV7OzeCqI+P1SHfNTRTp9XToNUn6cqd7wY4IKTtmlbJ GSPh+frLlsBrlAUu6IgrVLPRecqJCkEyOB7ZRIFxczuJXHQ4oEIpiq2cKRroxMDFvUdb n0Cg== X-Received: by 10.14.87.3 with SMTP id x3mr8562380eee.121.1375723881920; Mon, 05 Aug 2013 10:31:21 -0700 (PDT) Received: from [172.20.0.41] (196-210-102-70.dynamic.isadsl.co.za. [196.210.102.70]) by mx.google.com with ESMTPSA id j2sm266181eep.6.2013.08.05.10.31.20 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 05 Aug 2013 10:31:21 -0700 (PDT) Message-ID: <51FFE0C4.8020304@gmail.com> Date: Mon, 05 Aug 2013 19:28:36 +0200 From: Alan McKinnon User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130802 Thunderbird/17.0.7 Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Browsers cannot access WWW while ping and host utilities work as expected. References: <201308042057.57917.michaelkintzios@gmail.com> <201308051107.03261.michaelkintzios@gmail.com> <20130805125909.GL25510@server> <20130805163144.69653f43@marcec> <20130805144109.GM25510@server> In-Reply-To: <20130805144109.GM25510@server> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Archives-Salt: cc3ab0c9-3807-4457-b163-2a2146308f09 X-Archives-Hash: 99b89eec2d07fb96fbab296c812b7082 On 05/08/2013 16:41, Bruce Hill wrote: > On Mon, Aug 05, 2013 at 04:31:44PM +0200, Marc Joliet wrote: >> Am Mon, 5 Aug 2013 07:59:09 -0500 >> schrieb Bruce Hill : >> >>> If this is "the new kernel naming scheme of NICs", why this in dmesg: >>> >>> [ 4.725902] systemd-udevd[1176]: renamed network interface wlan0 to enp0s18f2u2 >>> >>> It looks as if systemd-udev renamed the NIC to me. Can you explain? >> >> It already has been explained in the previous NIC renaming discussion: what's >> broken is renaming a device within the kernels internal namespace, which >> contains eth*, wlan* (and maybe others). The problem is that there is a race >> condition with the kernel when renaming ethX to ethY. What you *can* do is >> rename ethX to somethingelseX or somethingelseY, because then you are not racing >> against the kernel to hand out device names. >> >> This is explained on the website that also explains the new default renaming >> scheme used by udev. I (and IIRC others, too) already linked to it in in the old >> thread, and the relevant news item also referenced it, but here it is again: >> >> http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/ > > The fact is that udev renamed the NIC. For the average Joe with one NIC (very > large percentage of users) this is a non sequitur. For those of us with 2 or > more NICs, myself included, we have already setup our systems to use multiple > NICs for a purpose and configured the system so that nothing can/will/needs to > rename subsequent NICs. > > My point is don't say "the new kernel naming scheme of NICs", say "the new > systemd naming scheme of NICs". > Let me see if I can clarify somewhat. eth0 can be considered the "kernel name" - the kernel named the NIC according to it's own rules using the info it had available. Kernel names depend on discovery order and to a lesser degree on the kernel code (a dev could change how things are done for example) enp0s18f2u2 can be considered the "userspace name" - it's derived from the slot the card is plugged into, and is set by udev. The kernel doesn't really care about this stuff, but you might. Most people think of their NICS on multi-NIC machines in terms of positions i.e. "third one on the left" and can't work with "whatever eth2 happens to be today" So why change this? Because you can't rely on ethX always being the same physical hardware. On a firewall or router, you absolutely need to rely on this. The udev scheme works around this by letting you specify exact rules that will always do what you want. Why was this changed rammed down your throat? Well, that is political. The udev maintainers (along with systemd) work for Red Hat. RH's market is almost totally servers, and big multi-nic ones at that. They really need consistent names, doubly so if the host is a virtualization host. The catch: RH (or more exactly the udev maintainer employed by RH) probably couldn't give a toss what you think or want, and went ahead and fixed their problem expecting you to "deal with it or shove off" Does all that fit better with what you see before you? [All of this is what I've inferred over months, it's my opinion in my words. You won't find this description with anyone else's name attached :-) ] -- Alan McKinnon alan.mckinnon@gmail.com