From owner-freebsd-net@freebsd.org Thu Nov 14 07:53:59 2019 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 C2C88178362 for ; Thu, 14 Nov 2019 07:53:59 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from hz.grosbein.net (hz.grosbein.net [IPv6:2a01:4f8:c2c:26d8::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "hz.grosbein.net", Issuer "hz.grosbein.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 47DDJP5Zc2z4f4K for ; Thu, 14 Nov 2019 07:53:57 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (eg.sd.rdtc.ru [IPv6:2a03:3100:c:13:0:0:0:5]) by hz.grosbein.net (8.15.2/8.15.2) with ESMTPS id xAE7rhA6003845 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 14 Nov 2019 07:53:45 GMT (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: ml@netfence.it Received: from [10.58.0.4] (dadv@[10.58.0.4]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTPS id xAE7rZ07021767 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Thu, 14 Nov 2019 14:53:35 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: net.inet.tcp.pmtud_blackhole_detection To: Andrea Venturoli , freebsd-net@freebsd.org References: From: Eugene Grosbein Message-ID: Date: Thu, 14 Nov 2019 14:53:36 +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: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=0.3 required=5.0 tests=BAYES_00,LOCAL_FROM, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.2 X-Spam-Report: * -2.3 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record * -0.0 SPF_PASS SPF: sender matches SPF record * 2.6 LOCAL_FROM From my domains X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on hz.grosbein.net X-Rspamd-Queue-Id: 47DDJP5Zc2z4f4K X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; 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 [-3.70 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[grosbein.net]; RCVD_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_SOME(0.00)[]; R_SPF_PERMFAIL(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; IP_SCORE(-1.60)[ip: (-4.04), ipnet: 2a01:4f8::/29(-2.28), asn: 24940(-1.65), country: DE(-0.01)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:24940, ipnet:2a01:4f8::/29, country:DE]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[] 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: Thu, 14 Nov 2019 07:53:59 -0000 14.11.2019 4:28, Andrea Venturoli wrote: > Running 11.3, is there any risk or downside in enabling this? > > I cannot reach my homebanking otherwise; I think either the bank has completely disabled ICMP or some router in between filters it. > > I see it's not enabled by default: is it just out of precaution? I guess it's a misfeature. It should be enabled by default. Feel free to enable it locally. Note I have not said it should be enabled unconditionally as there may be edge cases (high-load servers) when extra processing may be undesirable.