From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Yasevich Subject: Configuring the same IP on multiple addresses Date: Mon, 29 Oct 2007 14:03:37 -0400 Message-ID: <47262079.90507@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: netdev Return-path: Received: from atlrel6.hp.com ([156.153.255.205]:50345 "EHLO atlrel6.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755164AbXJ2SFK (ORCPT ); Mon, 29 Oct 2007 14:05:10 -0400 Received: from smtp2.fc.hp.com (smtp.cnd.hp.com [15.11.136.114]) by atlrel6.hp.com (Postfix) with ESMTP id 866BE3663A for ; Mon, 29 Oct 2007 14:04:01 -0400 (EDT) Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hi All Does anyone have a reason why Linux allows one to configure the same IP or IPv6 address on multiple interfaces? For IPv4, since linux implements a weak host model, assigning duplicate addresses doesn't make any sense, since the addresses really belong to the host and not the interface. For IPv6, I can see allowing duplicate link-locals since that's perfectly valid from the protocol perspective. However, duplicate globals are shouldn't be allows from the perspective of the address architecture. So, I am looking for technical reasons why this is permitted. Thanks -vlad