From owner-freebsd-net@freebsd.org Tue Jun 18 09:29:38 2019 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 1F32E15B2F96; Tue, 18 Jun 2019 09:29:38 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (eg.sd.rdtc.ru [IPv6:2a03:3100:c:13::5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "eg.sd.rdtc.ru", Issuer "eg.sd.rdtc.ru" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id D510E6BD1D; Tue, 18 Jun 2019 09:29:26 +0000 (UTC) (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: freebsd-net@freebsd.org Received: from [10.58.0.4] ([10.58.0.4]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTPS id x5I9TA3J073466 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Tue, 18 Jun 2019 16:29:10 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: Eliminating IPv6 (?) To: "Ronald F. Guilmette" References: <18748.1560843874@segfault.tristatelogic.com> Cc: freebsd-net@freebsd.org, freebsd-questions@freebsd.org From: Eugene Grosbein Message-ID: Date: Tue, 18 Jun 2019 16:29:02 +0700 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <18748.1560843874@segfault.tristatelogic.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: D510E6BD1D X-Spamd-Bar: / Authentication-Results: mx1.freebsd.org; spf=permerror (mx1.freebsd.org: domain of eugen@grosbein.net uses mechanism not recognized by this client) smtp.mailfrom=eugen@grosbein.net X-Spamd-Result: default: False [-0.17 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.42)[-0.418,0]; RCVD_TLS_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_DN_SOME(0.00)[]; NEURAL_HAM_LONG(-0.24)[-0.238,0]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[grosbein.net]; NEURAL_SPAM_SHORT(0.08)[0.085,0]; MX_INVALID(0.50)[greylisted]; TO_MATCH_ENVRCPT_SOME(0.00)[]; R_SPF_PERMFAIL(0.00)[]; IP_SCORE(0.00)[country: RU(0.01)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:29072, ipnet:2a03:3100::/32, country:RU]; MID_RHS_MATCH_FROM(0.00)[]; SUBJECT_HAS_QUESTION(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Jun 2019 09:29:38 -0000 18.06.2019 14:44, Ronald F. Guilmette wrote: >>> How can I turn off IPv6 entirely without rebuilding the kernel? >> You cannot. GENERIC kernel specifically enables IPv6 support and you need to >> disable it at compile time. >> And if you do, you better rebuild the world too using WITHOUT_INET6=yes in the >> /etc/src.conf >> or else some utilities compiled with INET6 by default will query kernel >> for IPv6-specific data (like routing entries) and complain that your kernel does >> not know about it. >> >> World built WITHOUT_INET6 has no such rough edges. > > OK, so I obviously expressed myself badly. Let me try again. > > IPv6 support is enabled in a the stock kernel. OK. Fine. But just because > that feature is present in the kernel, that does not imply that anything in > userland -has- to actually make any use of it at all. > > *Something* is doing ifconfig on my loopback (lo0) interface. What is that > thing and how can I get it to stop doing that? It is not userland. It is a kernel itself. IPv6 standards are very different comparing to IPv4. They mandate some level of actual usage of IPv6. Easiest (and sometimes only) way to get rid of this is to rebuilt the kernel.