From owner-freebsd-net@freebsd.org Thu Sep 29 03:11:10 2016 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 60AD9BE21DB for ; Thu, 29 Sep 2016 03:11:10 +0000 (UTC) (envelope-from prox@prolixium.com) Received: from nox.prolixium.com (nox.prolixium.com [IPv6:2620:6:2000:104::1e]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4474613BE for ; Thu, 29 Sep 2016 03:11:10 +0000 (UTC) (envelope-from prox@prolixium.com) Received: from prox by nox.prolixium.com with local (Exim 4.87) (envelope-from ) id 1bpRka-0001R6-Bj for freebsd-net@FreeBSD.org; Wed, 28 Sep 2016 22:11:08 -0500 Date: Wed, 28 Sep 2016 22:11:08 -0500 From: Mark Kamichoff To: freebsd-net@FreeBSD.org Subject: ICMPv6 HL Exceeded Messages Generated from Wrong Address Message-ID: <20160929031108.GA1530@prolixium.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: prox@prolixium.com X-SA-Exim-Scanned: No (on nox.prolixium.com); SAEximRunCond expanded to false X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.23 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, 29 Sep 2016 03:11:10 -0000 Hi - I've got FreeBSD 11* in a VM acting as an IPv6 router with a bunch of tunnel interfaces and a couple virtio interfaces. I'm seeing some odd behavior related to ICMPv6 HL exceeded messages (type 3 code 0) when running traceroutes. Specifically, the FreeBSD box emits the ICMPv6 messages using the outgoing interface address (ie, toward traceroute destination) instead of the incoming interface address (expected). I've a FreeBSD 10.3 box that ran with almost an identical setup (em instead of virtio, since it was bare metal) that didn't experience this behavior. Here's a few examples, along with an obligatory ASCII-art diagram: https://www.prolixium.com/share/txt/fbsd11-icmpv6hle.txt I'm not willing to rule out some misconfiguration at this point, but I really haven't tuned any knobs that I believe would affect this. Is anyone else with a FreeBSD 11 IPv6 router seeing this type of behavior? What parts of my configuration should I share? - Mark * = FreeBSD 11.0-PRERELEASE #0 r306218: Thu Sep 22 22:03:59 EDT 2016 -- Mark Kamichoff prox@prolixium.com http://www.prolixium.com/