From mboxrd@z Thu Jan 1 00:00:00 1970 From: Albert Krenz Subject: How does the linux kernel select the MAC address for TAP devices? Date: Mon, 16 Jun 2014 10:00:14 +0200 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 To: netdev@vger.kernel.org Return-path: Received: from mail-qa0-f44.google.com ([209.85.216.44]:53393 "EHLO mail-qa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751320AbaFPIAP (ORCPT ); Mon, 16 Jun 2014 04:00:15 -0400 Received: by mail-qa0-f44.google.com with SMTP id hw13so5714579qab.17 for ; Mon, 16 Jun 2014 01:00:15 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: As stated in the email subject: Where does the kernel get the used MAC-Adress for a newly create TAP device? Are they randomly generated or does it select one from a fixed pool of reserved MAC-Adresses? I have not found any official documentation about the selection of MAC-addresses for TAP-devices. Most sites like http://backreference.org/2010/03/26/tuntap-interface-tutorial/ state that the MAC addresses are auto-generated and can be changed. But they do not explain the generation rules. Does anyone know an official document (preferably from kernel.org) explaining the MAC selection process? Or is it only explained in the Source?