From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: netlink NETLINK_ROUTE failure & Can the kernel really handle IPv6 properly Date: Wed, 01 Oct 2014 23:30:32 +0200 Message-ID: <1412199032.2532289.174101717.2D6510D0@webmail.messagingengine.com> References: <542C63FE.9080807@emagii.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit To: Ulf Samuelsson , Linux Netdev List Return-path: Received: from out5-smtp.messagingengine.com ([66.111.4.29]:57941 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751516AbaJAVad (ORCPT ); Wed, 1 Oct 2014 17:30:33 -0400 Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by gateway2.nyi.internal (Postfix) with ESMTP id 9AE8F20B78 for ; Wed, 1 Oct 2014 17:30:32 -0400 (EDT) In-Reply-To: <542C63FE.9080807@emagii.com> Sender: netdev-owner@vger.kernel.org List-ID: Hello, On Wed, Oct 1, 2014, at 22:28, Ulf Samuelsson wrote: > BTW, the problem I am trying to solve is how to connect to an I/F with > an IPv6 link-local address. > > An existing kernel module waits for a NETDEV_UP event, and then tries to > communicate > with the link-local address. > > This will fail, because (according to a colleague) the I/F enters a > "tentative" state, > where it is trying to decide if it is unique or not. > It will remain in that state for 1-2 seconds, and only afterwards is the > link-local address > available for normal use. > > The guys writing the module, claim that the kernel is using NETDEV_UP. > There is very little code in the kernel using NETLINK_ROUTE, even in > latest stable. > It is using NETDEV_UP. > > If my colleague is right, the kernel really cannot handle IPv6 > link-local addresses properly. Sorry, I cannot really follow you, can you send example code or be a bit more precise? Thanks, Hannes