From owner-freebsd-questions@freebsd.org Mon Oct 26 20:44:19 2015 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 638DAA1EC84 for ; Mon, 26 Oct 2015 20:44:19 +0000 (UTC) (envelope-from milios@ccsys.com) Received: from cargobay.net (cargobay.net [198.178.123.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 3BD641760; Mon, 26 Oct 2015 20:44:18 +0000 (UTC) (envelope-from milios@ccsys.com) Received: from [192.168.0.12] (cblmdm72-240-160-19.buckeyecom.net [72.240.160.19]) by cargobay.net (Postfix) with ESMTPSA id 59671175; Mon, 26 Oct 2015 20:44:11 +0000 (UTC) Subject: Re: NIC naming To: Terje Elde , Matthew Seaman References: <562E4D92.3000308@gmail.com> <562E551F.6060406@freebsd.org> <0746B048-19AB-4AA6-8439-4DF7A08D10AE@elde.net> Cc: freebsd-questions@freebsd.org From: "Chad J. Milios" Message-ID: <562E909B.5050408@ccsys.com> Date: Mon, 26 Oct 2015 16:44:11 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <0746B048-19AB-4AA6-8439-4DF7A08D10AE@elde.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Oct 2015 20:44:19 -0000 On 10/26/2015 2:16 PM, Terje Elde wrote: > >> On 26 Oct 2015, at 17:30, Matthew Seaman wrote: >> >> This probably doesn't solve your problem, which appears to be knowing >> which of the ethernet ports on your machine is em0 -- the usual method >> to do that is by ifconfig'ing everything else down and then testing with >> a network cable until you find the working port. However it might help >> clarify the system configuration. > ifconfig will give you the MAC of the card. I'm not sure if there's a standard tool for it, but it should be easy to do something like "rename the card with MAC address X to Y" you can put the following one-liner (fix if your email client breaks) directly into /etc/rc.conf or /etc/rc.conf.local (replace 01:23:45:67:89:ab with your "main" card's MAC address and that interface will always be named, in this example net0: eval setvar `ifconfig | while read a b; do if [ "$b" != "${b#flags=}" ]; then c=${a%:}; fi; if [ "$a" = ether -a "$b" = 01:23:45:67:89:ab ]; then echo ifconfig_${c}_name net0; fi; done` > Personally, I've started renaming along the lines of renaming em0 to em_lan0, em1 to em_wan1 and so on. Makes it a bit easier to see what's going on, both for when another admin might inherit the box, and also for myself, if I haven't touched the box in a few years. you may replace net0 with legal names such as up0, up1, down0, down1, down2, down4 (or in#, out#, wan#, lan#) etc. whatever makes most sense to describe your use case (just not wlan#. use wifi# or wphy# for your wlan#'s phy interface): name_mac () { eval setvar `ifconfig | while read a b; do if [ "$b" != "${b#flags=}" ]; then c=${a%:}; fi; if [ "$a" = ether -a "$b" = $2 ]; then echo ifconfig_${c}_name $1; fi; done` } name_mac up0 aa:aa:aa:aa:aa:aa name_mac down0 bb:bb:bb:bb:bb:bb name_mac down1 cc:cc:cc:cc:cc:cc > Sure, you could argue all of this should be documented somewhere as well - and you wouldn't be wrong - but renaming makes things obvious where the next admin will look, not just in some doc that might be somewhere he didn't. > > Terje -Chad J. Milios P.S. any snippets of code contained in this email are hereby placed in the public domain.