From owner-freebsd-questions@freebsd.org Mon Jul 5 15:46:01 2021 Return-Path: Delivered-To: freebsd-questions@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 6CB4765F309 for ; Mon, 5 Jul 2021 15:46:01 +0000 (UTC) (envelope-from freebsd-lists-5@thismonkey.com) Received: from mail-01.thismonkey.com (mail-01.thismonkey.com [IPv6:2406:3400:35e:6602::a01:232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "thismonkey.com", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4GJVQZ1V6jz4c5Z for ; Mon, 5 Jul 2021 15:45:57 +0000 (UTC) (envelope-from freebsd-lists-5@thismonkey.com) Received: from mailhub-01.thismonkey.com (mailhub-01.thismonkey.com [IPv6:2406:3400:35e:6601:0:0:a01:11e]) by mail-01.thismonkey.com (8.15.2/8.15.2) with ESMTP id 165FjjwN043223 for ; Tue, 6 Jul 2021 01:45:45 +1000 (EST) (envelope-from freebsd-lists-5@thismonkey.com) X-TM-Via-MX: mailhub-01.thismonkey.com Received: from utility-01.thismonkey.com (utility-01.thismonkey.com [IPv6:2406:3400:35e:6601:0:0:a01:120]) by mailhub-01.thismonkey.com (8.15.2/8.15.2) with ESMTPS id 165Fjj5C018282 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT) for ; Tue, 6 Jul 2021 01:45:45 +1000 (AEST) (envelope-from freebsd-lists-5@thismonkey.com) Received: from utility-01.thismonkey.com (localhost [127.0.0.1]) by utility-01.thismonkey.com (8.16.1/8.16.1) with ESMTP id 165FjjLS029270 for ; Tue, 6 Jul 2021 01:45:45 +1000 (EST) (envelope-from freebsd-lists-5@thismonkey.com) Received: (from root@localhost) by utility-01.thismonkey.com (8.16.1/8.16.1/Submit) id 165Fjida029269 for freebsd-questions@freebsd.org; Tue, 6 Jul 2021 01:45:44 +1000 (EST) (envelope-from freebsd-lists-5@thismonkey.com) Date: Tue, 6 Jul 2021 01:45:44 +1000 From: Scott To: freebsd-questions@freebsd.org Subject: Specifying IPv6 off-link for a subnet Message-ID: Mail-Followup-To: freebsd-questions@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Virus-Scanned: clamav-milter 0.102.2 at mail-01.thismonkey.com X-Virus-Status: Clean X-Rspamd-Queue-Id: 4GJVQZ1V6jz4c5Z X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=pass (policy=none) header.from=thismonkey.com; spf=pass (mx1.freebsd.org: domain of freebsd-lists-5@thismonkey.com designates 2406:3400:35e:6602::a01:232 as permitted sender) smtp.mailfrom=freebsd-lists-5@thismonkey.com X-Spamd-Result: default: False [-3.80 / 15.00]; MID_RHS_MATCH_FROM(0.00)[]; RBL_DBL_DONT_QUERY_IPS(0.00)[2406:3400:35e:6602::a01:232:from]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; MIME_GOOD(-0.10)[text/plain]; TO_DN_NONE(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[freebsd-questions@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; SPAMHAUS_ZRD(0.00)[2406:3400:35e:6602::a01:232:from:127.0.2.255]; RCVD_COUNT_THREE(0.00)[4]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_LONG(-1.00)[-1.000]; DMARC_POLICY_ALLOW(-0.50)[thismonkey.com,none]; NEURAL_HAM_SHORT(-1.00)[-1.000]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:10143, ipnet:2406:3400:340::/42, country:AU]; RCVD_TLS_LAST(0.00)[]; MAILMAN_DEST(0.00)[freebsd-questions] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Jul 2021 15:46:01 -0000 Hi all, I have a few FreeBSD hosts with IPv6 and am struggling to get FreeBSD to respect an RA with the on-link flag un-set. I have manually configured IPv6 on the interfaces: ifconfig_vmx0_ipv6="inet6 xx::yy prefer_source accept_rtadv -autoconf no_radr" The prefix appears in the prefix list as: # ndp -p xx::/64 if=vmx0 flags=LO vltime=infinity, pltime=infinity, expire=Never, ref=1 No advertising router Note how the L flag is set. ifconfig does not seem to allow for specifying off-link (or no on-link) for a subnet, so I was hoping FreeBSD would rely on the router RA. According to rfc5942, 4.1 states (edited): The assignment of an IPv6 address through manual configuration MUST NOT implicitly cause a prefix derived from that address to be treated as on-link. A host considers a prefix to be on-link only through explicit means. Here's the received RA: 01:26:48.355186 IP6 (class 0xe0, hlim 255, next-header ICMPv6 (58) payload length: 64) fe80::1 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 64 hop limit 64, Flags [none], pref high, router lifetime 1800s, reachable time 0ms, retrans timer 0ms source link-address option (1), length 8 (1): 00:00:5e:00:02:02 mtu option (5), length 8 (1): 9000 prefix info option (3), length 32 (4): xx::/64, Flags [none], valid time 3600s, pref. time 60s Note that there is no L flag set, so the prefix is off-link. However FreeBSD does not update the prefix list accordingly. Am I doing something wrong here? Or is FreeBSD not following the rules? Thanks, Scott