From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roy Marples Subject: Re: [PATCH] ipv6: do not add link-local address if one already exists Date: Mon, 11 Aug 2014 00:05:13 +0000 Message-ID: References: <1407703032.2161.22.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, "\"David S. Miller\\" , Alexey Kuznetsov "\"\"" , Hideaki YOSHIFUJI , "\"Patrick"@marples.name, McHardy@marples.name, " "@marples.name To: Hannes Frederic Sowa Return-path: Received: from uberserver.marples.name ([77.75.106.61]:56121 "EHLO mail.marples.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751689AbaHKAFQ (ORCPT ); Sun, 10 Aug 2014 20:05:16 -0400 In-Reply-To: <1407703032.2161.22.camel@localhost> Sender: netdev-owner@vger.kernel.org List-ID: Hi On 2014-08-10 20:37, Hannes Frederic Sowa wrote: > On So, 2014-08-10 at 19:56 +0000, Roy Marples wrote: >> Currently the kernel will always add an IPv6 link-local address >> based on the hardware address when the interface is brought up. >> This is probably based on the assumption that userland would >> never add one before the interface is brought up. >> >> However, one at least one userland application (dhcpcd) does this so >> it can implement RFC7217 which can be used for link-local addresses >> as well. >> >> Attached is a patch which checks to see if a link-local address exists >> before indiscriminately adding one. > > Please have a look at: > https://git.kernel.org/cgit/linux/kernel/git/davem/net-next.git/commit/?id=bc91b0f07ada5535427373a4e2050877bcc12218 > > This was recently implemented just for this specific case. Is that tunable available in /proc or /sys? I'm not overly keen on adding a netlink call just for that in dhcpcd, it would be a lot of bloat compared to the kernel patch. Roy