From owner-freebsd-net@freebsd.org Wed Jun 19 20:51:16 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 CCC2415C9DA6; Wed, 19 Jun 2019 20:51:16 +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 D415582663; Wed, 19 Jun 2019 20:51:15 +0000 (UTC) (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: freebsd-questions@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 x5JKpAh6093581 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Thu, 20 Jun 2019 03:51:10 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: Eliminating IPv6 (?) To: "Rodney W. Grimes" References: <201906191542.x5JFgQQ2018770@gndrsh.dnsmgr.net> Cc: "Ronald F. Guilmette" , freebsd-questions@freebsd.org, freebsd-net@freebsd.org From: Eugene Grosbein Message-ID: <1633b96e-15ba-9933-abea-46e7b4f0e6a2@grosbein.net> Date: Thu, 20 Jun 2019 03:51:01 +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: <201906191542.x5JFgQQ2018770@gndrsh.dnsmgr.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: D415582663 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 [0.63 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.60)[-0.599,0]; RCVD_TLS_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; TO_DN_SOME(0.00)[]; NEURAL_SPAM_SHORT(0.62)[0.621,0]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[grosbein.net]; MX_INVALID(0.50)[cached]; TO_MATCH_ENVRCPT_SOME(0.00)[]; R_SPF_PERMFAIL(0.00)[]; NEURAL_SPAM_LONG(0.20)[0.205,0]; 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: Wed, 19 Jun 2019 20:51:17 -0000 19.06.2019 22:42, Rodney W. Grimes wrote: >> 18.06.2019 10:10, 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. > I have not seen these issues, can you give a specific example that fails? Other than kernel/userland interaction (that may be not relevant anymore for modern FreeBSD), that's basically about making network connections (such as telnet etc.) to FQDNs resolved to IPv6 addresses supported by binaries (and resolver being userland beast) but not kernel/routing table. > A netstat -rn on a v4 only kernel simple reports the v4 table, and iirc a > netstat -rn6 returns a "Protocol not supported error" as should all other > things. >> World built WITHOUT_INET6 has no such rough edges. > I find that actually causes me more issues, as then my > netstat -rn6 returns a hard error due to: > case '6': > #ifdef INET6 > af = AF_INET6; > #else > errx(1, "IPv6 support is not compiled in"); > #endif Seems very logical to me. Do we have a script in base running "netstat -rn6" and breaking on this?