From owner-freebsd-net@FreeBSD.ORG Thu Mar 27 16:48:21 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 047B639D for ; Thu, 27 Mar 2014 16:48:21 +0000 (UTC) Received: from smtp.domeneshop.no (smtp.domeneshop.no [194.63.252.54]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id BAE578BA for ; Thu, 27 Mar 2014 16:48:20 +0000 (UTC) Received: from uib-guest.uib.no ([129.177.138.114]:58447 helo=[10.103.254.196]) by smtp.domeneshop.no with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.72) (envelope-from ) id 1WTD5o-0004iA-A5 for freebsd-net@freebsd.org; Thu, 27 Mar 2014 17:23:48 +0100 Message-ID: <5334509B.8010706@sande.im> Date: Thu, 27 Mar 2014 17:23:55 +0100 From: Mikal Sande User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: FreeBSD Net Subject: ipv6 neighbor cache question Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 Mar 2014 16:48:21 -0000 Is the IPv6 neighbor cache supposed to not inlcude incomplete entries? When my freebsd box resolves a previously unknown ipv6 address with ndp it does not add anything to the neighbor cache before it gets a reachability confirmation. I have viewed the neighbor cache with ndp -a. The ipv6 addresses in question are local, so I am pretty sure that on-link determination is not interfering. The same thing happens with both link-local and global addresses. When I ping an unused ipv6 address I do not find any corresponding incomplete entry in the neighbor cache afterwards. But, if I ping an unused ipv4 address i do find an incomplete entry in the arp cache. I am curious as to why this behavior occurs. Is it intentional? Is it by design? The reason for my curiosity is that I have not observed this behavior in other OSes such as linux and openbsd. My box is currently running. FreeBSD hostname 10.0-RELEASE FreeBSD 10.0-RELEASE #0 r260789: Thu Jan 16 22:34:59 UTC 2014 root@snap.freebsd.org:/usr/obj/usr/src/sys/GENERIC amd64 -- Mikal Sande