From owner-freebsd-net@freebsd.org Mon Dec 23 09:46:00 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 F28BF1EB121 for ; Mon, 23 Dec 2019 09:46:00 +0000 (UTC) (envelope-from bu7cher@yandex.ru) Received: from forward100p.mail.yandex.net (forward100p.mail.yandex.net [77.88.28.100]) (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 47hDxg3LPvz4RbJ for ; Mon, 23 Dec 2019 09:45:59 +0000 (UTC) (envelope-from bu7cher@yandex.ru) Received: from mxback28g.mail.yandex.net (mxback28g.mail.yandex.net [IPv6:2a02:6b8:0:1472:2741:0:8b7:328]) by forward100p.mail.yandex.net (Yandex) with ESMTP id E9DF35980C9D; Mon, 23 Dec 2019 12:45:56 +0300 (MSK) Received: from iva7-d5f903270d57.qloud-c.yandex.net (iva7-d5f903270d57.qloud-c.yandex.net [2a02:6b8:c0c:6e00:0:640:d5f9:327]) by mxback28g.mail.yandex.net (mxback/Yandex) with ESMTP id BgtVbaVaGe-juv8SFXC; Mon, 23 Dec 2019 12:45:56 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1577094356; bh=I9kLkUw1L3O7Nezobj3m8CZWWSuEVRCgxsRy8MkEHKI=; h=In-Reply-To:To:From:Subject:Date:References:Message-ID; b=HeLcEi/n+w4puYVaFIiEYvjdM3QkjQ5Q52hV+YJtoFGlstGehZKtqZh9vAKaItl+s cOZcxUBXNbvCPtARFkPw+tiHEk9X8Di/s1VGTtAdbiM7zCqMkIpK/rv1MxYG42ddV6 KNNcWft7XovpE1SJN62cMlzAbJsK10/TG01R/v5U= Received: by iva7-d5f903270d57.qloud-c.yandex.net (smtp/Yandex) with ESMTPSA id 48MQTkya9r-juUe5REI; Mon, 23 Dec 2019 12:45:56 +0300 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client certificate not present) Subject: Re: IPSec transport mode, mtu, fragmentation... From: "Andrey V. Elsukov" To: Victor Sudakov , freebsd-net@freebsd.org References: <20191220152314.GA55278@admin.sibptus.ru> <20191220160357.GB56081@admin.sibptus.ru> <20191220162233.GA56815@admin.sibptus.ru> <55eeca4c-9633-339a-f521-b0db462cc1d6@yandex.ru> Openpgp: id=E6591E1B41DA1516F0C9BC0001C5EA0410C8A17A Autocrypt: addr=bu7cher@yandex.ru; prefer-encrypt=mutual; keydata= mQENBEwBF1kBCADB9sXFhBEUy8qQ4X63Y8eBatYMHGEFWN9ypS5lI3RE6qQW2EYbxNk7qUC5 21YIIS1mMFVBEfvR7J9uc7yaYgFCEb6Sce1RSO4ULN2mRKGHP3/Sl0ijZEjWHV91hY1YTHEF ZW/0GYinDf56sYpDDehaBF5wkWIo1+QK5nmj3vl0DIDCMNd7QEiWpyLVwECgLX2eOAXByT8B bCqVhJGcG6iFP7/B9Ll6uX5gb8thM9LM+ibwErDBVDGiOgvfxqidab7fdkh893IBCXa82H9N CNwnEtcgzh+BSKK5BgvPohFMgRwjti37TSxwLu63QejRGbZWSz3OK3jMOoF63tCgn7FvABEB AAG0JUFuZHJleSBWLiBFbHN1a292IDxidTdjaGVyQHlhbmRleC5ydT6JATgEEwECACIFAkwB F1kCGwMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEAHF6gQQyKF6qmYIAI6ekfm1VA4T vqankI1ISE6ku4jV7UlpIQlEbE7/8n3Zd6teJ+pGOQhN5qk8QE7utdPdbktAzi+x7LIJVzUw 4TywZLXGrkP7VKYkfg6oyCGyzITghefQeJtr2TN4hYCkzPWpylkue8MtmqfZv/6royqwTbN+ +E09FQNvTgRUYJYTeQ1qOsxNRycwvw3dr2rOfuxShbzaHBB1pBIjGrMg8fC5pd65ACH5zuFV A0CoTNGMDrEZSfBkTW604UUHFFXeCoC3dwDZRKOWJ3GmMXns65Ai5YkA63BSHEE1Qle3VBhd cG1w0CB5FBV3pB27UVnf0jEbysrDqW4qN7XMRFSWNAy5AQ0ETAEXWQEIAJ2p6l9LBoqdH/0J PEFDY2t2gTvAuzz+8zs3R03dFuHcNbOwjvWCG0aOmVpAzkRa8egn5JB4sZaFUtKPYJEQ1Iu+ LUBwgvtXf4vWpzC67zs2dDuiW4LamH5p6xkTD61aHR7mCB3bg2TUjrDWn2Jt44cvoYxj3dz4 S49U1rc9ZPgD5axCNv45j72tggWlZvpefThP7xT1OlNTUqye2gAwQravXpZkl5JG4eOqJVIU X316iE3qso0iXRUtO7OseBf0PiVmk+wCahdreHOeOxK5jMhYkPKVn7z1sZiB7W2H2TojbmcK HZC22sz7Z/H36Lhg1+/RCnGzdEcjGc8oFHXHCxUAEQEAAYkBHwQYAQIACQUCTAEXWQIbDAAK CRABxeoEEMihegkYCAC3ivGYNe2taNm/4Nx5GPdzuaAJGKWksV+w9mo7dQvU+NmI2az5w8vw 98OmX7G0OV9snxMW+6cyNqBrVFTu33VVNzz9pnqNCHxGvj5dL5ltP160JV2zw2bUwJBYsgYQ WfyJJIM7l3gv5ZS3DGqaGIm9gOK1ANxfrR5PgPzvI9VxDhlr2juEVMZYAqPLEJe+SSxbwLoz BcFCNdDAyXcaAzXsx/E02YWm1hIWNRxanAe7Vlg7OL+gvLpdtrYCMg28PNqKNyrQ87LQ49O9 50IIZDOtNFeR0FGucjcLPdS9PiEqCoH7/waJxWp6ydJ+g4OYRBYNM0EmMgy1N85JJrV1mi5i Message-ID: <7cc2f101-c870-c517-8e01-d656079a75be@yandex.ru> Date: Mon, 23 Dec 2019 12:44:25 +0300 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <55eeca4c-9633-339a-f521-b0db462cc1d6@yandex.ru> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="HIqi4YVaYla9a0DB6sND85RxRSVBk6vJ9" X-Rspamd-Queue-Id: 47hDxg3LPvz4RbJ X-Spamd-Bar: ------ Authentication-Results: mx1.freebsd.org; dkim=pass header.d=yandex.ru header.s=mail header.b=HeLcEi/n; dmarc=pass (policy=none) header.from=yandex.ru; spf=pass (mx1.freebsd.org: domain of bu7cher@yandex.ru designates 77.88.28.100 as permitted sender) smtp.mailfrom=bu7cher@yandex.ru X-Spamd-Result: default: False [-6.20 / 15.00]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:77.88.0.0/18]; FREEMAIL_FROM(0.00)[yandex.ru]; HAS_ATTACHMENT(0.00)[]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[yandex.ru:+]; RCPT_COUNT_TWO(0.00)[2]; DMARC_POLICY_ALLOW(-0.50)[yandex.ru,none]; SIGNED_PGP(-2.00)[]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:+,3:~]; RCVD_TLS_LAST(0.00)[]; RCVD_IN_DNSWL_LOW(-0.10)[100.28.88.77.list.dnswl.org : 127.0.5.1]; ASN(0.00)[asn:13238, ipnet:77.88.0.0/18, country:RU]; MID_RHS_MATCH_FROM(0.00)[]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[yandex.ru:s=mail]; FROM_HAS_DN(0.00)[]; FREEMAIL_ENVFROM(0.00)[yandex.ru]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.20)[multipart/signed,multipart/mixed,text/plain]; IP_SCORE(0.00)[ipnet: 77.88.0.0/18(-4.78), asn: 13238(-3.79), country: RU(0.01)]; IP_SCORE_FREEMAIL(0.00)[]; DWL_DNSWL_LOW(-1.00)[yandex.ru.dwl.dnswl.org : 127.0.5.1]; TO_MATCH_ENVRCPT_SOME(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: Mon, 23 Dec 2019 09:46:01 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --HIqi4YVaYla9a0DB6sND85RxRSVBk6vJ9 Content-Type: multipart/mixed; boundary="ssEhZlwYdO6WvTXOoOpmRuCelT03eakSl"; protected-headers="v1" From: "Andrey V. Elsukov" To: Victor Sudakov , freebsd-net@freebsd.org Message-ID: <7cc2f101-c870-c517-8e01-d656079a75be@yandex.ru> Subject: Re: IPSec transport mode, mtu, fragmentation... References: <20191220152314.GA55278@admin.sibptus.ru> <20191220160357.GB56081@admin.sibptus.ru> <20191220162233.GA56815@admin.sibptus.ru> <55eeca4c-9633-339a-f521-b0db462cc1d6@yandex.ru> In-Reply-To: <55eeca4c-9633-339a-f521-b0db462cc1d6@yandex.ru> --ssEhZlwYdO6WvTXOoOpmRuCelT03eakSl Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 23.12.2019 12:39, Andrey V. Elsukov wrote: > On 20.12.2019 19:22, Victor Sudakov wrote: >>> What's the root of the problem? ESP packets cannot get fragmented or >>> what?=20 >> >> Wireshark has shown that the "Don't Fragment" flag is set on all ESP >> (protocol 50) packets. Who does this, why, and how can I switch it off= >> globally? >=20 > Hi, >=20 > I think this DF flag is originally from TCP packet. > ESP xform for transport mode just replaces protocol in IP header and > adds some info to the end of a packet. This is controlled by net.inet.tcp.path_mtu_discovery variable. TCP won't set IP_DF flag if you disable this feature. --=20 WBR, Andrey V. 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