From owner-freebsd-net@freebsd.org Sat Feb 20 04:33:04 2021 Return-Path: Delivered-To: freebsd-net@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 4BCEA534DB0 for ; Sat, 20 Feb 2021 04:33:04 +0000 (UTC) (envelope-from bc979@lafn.org) Received: from mailman.nyi.freebsd.org (mailman.nyi.freebsd.org [IPv6:2610:1c1:1:606c::50:13]) by mx1.freebsd.org (Postfix) with ESMTP id 4DjFtS0pFQz4g9s for ; Sat, 20 Feb 2021 04:33:04 +0000 (UTC) (envelope-from bc979@lafn.org) Received: by mailman.nyi.freebsd.org (Postfix) id 1B754534D55; Sat, 20 Feb 2021 04:33:04 +0000 (UTC) Delivered-To: net@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 1B3DD534ED2 for ; Sat, 20 Feb 2021 04:33:04 +0000 (UTC) (envelope-from bc979@lafn.org) Received: from mail.sermon-archive.info (sermon-archive.info [71.177.216.148]) by mx1.freebsd.org (Postfix) with ESMTP id 4DjFtQ734Tz4g4b for ; Sat, 20 Feb 2021 04:33:02 +0000 (UTC) (envelope-from bc979@lafn.org) Received: from [10.0.1.251] (mini [10.0.1.251]) by mail.sermon-archive.info (Postfix) with ESMTPSA id 4DjFtJ2N1Zz2fjQB for ; Fri, 19 Feb 2021 20:32:56 -0800 (PST) From: Doug Hardie Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.60.0.2.21\)) Subject: Re: IPv6 Fragmentation Date: Fri, 19 Feb 2021 20:32:55 -0800 References: <472A2B49-9BEC-4335-B6FB-AC4DAA0F0310@lurchi.franken.de> To: "net@freebsd.org" In-Reply-To: <472A2B49-9BEC-4335-B6FB-AC4DAA0F0310@lurchi.franken.de> Message-Id: X-Mailer: Apple Mail (2.3654.60.0.2.21) X-Virus-Scanned: clamav-milter 0.103.0 at mail X-Virus-Status: Clean X-Rspamd-Queue-Id: 4DjFtQ734Tz4g4b X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of bc979@lafn.org designates 71.177.216.148 as permitted sender) smtp.mailfrom=bc979@lafn.org X-Spamd-Result: default: False [-2.70 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; FROM_HAS_DN(0.00)[]; RBL_DBL_DONT_QUERY_IPS(0.00)[71.177.216.148:from]; MV_CASE(0.50)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[net@freebsd.org]; DMARC_NA(0.00)[lafn.org: no valid DMARC record]; RCPT_COUNT_ONE(0.00)[1]; SPAMHAUS_ZRD(0.00)[71.177.216.148:from:127.0.2.255]; R_SPF_ALLOW(-0.20)[+ip4:71.177.216.148/32]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-1.00)[-1.000]; TO_DN_EQ_ADDR_ALL(0.00)[]; RCVD_NO_TLS_LAST(0.10)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:5650, ipnet:71.177.216.0/23, country:US]; RCVD_COUNT_TWO(0.00)[2]; MAILMAN_DEST(0.00)[net] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Feb 2021 04:33:04 -0000 > On 19 February 2021, at 01:48, Michael Tuexen = wrote: >=20 >> On 19. Feb 2021, at 03:29, Doug Hardie wrote: >>=20 >> I don't know if this is a feature or a bug. On FreeBSD 9, the = following ping worked: >>=20 >> ping6 -s 5000 -b 6000 fe80::213:72ff:fec3:180f%dc0 > I don't have a dc0 interface, but using re0 at one side and bge at the = other, I get > with FreeBSD CURRENT: > tuexen@cirrus:~ % ping6 -s 5000 -b 6000 fe80::2e09:4dff:fe00:c00%re0 > PING6(5048=3D40+8+5000 bytes) fe80::aaa1:59ff:fe0c:da92%re0 --> = fe80::2e09:4dff:fe00:c00%re0 > 5008 bytes from fe80::2e09:4dff:fe00:c00%re0, icmp_seq=3D0 hlim=3D255 = time=3D0.393 ms > 5008 bytes from fe80::2e09:4dff:fe00:c00%re0, icmp_seq=3D1 hlim=3D255 = time=3D0.419 ms > 5008 bytes from fe80::2e09:4dff:fe00:c00%re0, icmp_seq=3D2 hlim=3D255 = time=3D0.354 ms > 5008 bytes from fe80::2e09:4dff:fe00:c00%re0, icmp_seq=3D3 hlim=3D255 = time=3D0.446 ms > 5008 bytes from fe80::2e09:4dff:fe00:c00%re0, icmp_seq=3D4 hlim=3D255 = time=3D0.421 ms > 5008 bytes from fe80::2e09:4dff:fe00:c00%re0, icmp_seq=3D5 hlim=3D255 = time=3D0.372 ms > ^C > --- fe80::2e09:4dff:fe00:c00%re0 ping6 statistics --- > 6 packets transmitted, 6 packets received, 0.0% packet loss > round-trip min/avg/max/std-dev =3D 0.354/0.401/0.446/0.031 ms >=20 > Best regards > Michael >>=20 >> It had to be stopped, but it returned the number of ping responses = received along with statistics. >>=20 >> With FreeBSD 12.2 and 13.0-BETA2, it returns 100% packet loss. = tcpdump shows that it properly fragments the data, sends it, the other = end receives it and sends back the ACKs. The ACKs are received, but = somehow ping doesn't find out that the packets were received. >>=20 >> Without the -s and -b arguments, it works and you get 100% packets = received. I found the problem. pf does not handle IPv6 packets that are = fragmented the obvious way. I suspect it is because icmp header is only = in the first fragment. I had to reassemble fragments in pf in order to = make the large pings work. -- Doug