Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E464AC2D0DA for ; Thu, 26 Dec 2019 15:36:47 +0000 (UTC) Received: from krantz.zx2c4.com (krantz.zx2c4.com [192.95.5.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 82B8D206A4 for ; Thu, 26 Dec 2019 15:36:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=lost-frequencies.eu header.i=@lost-frequencies.eu header.b="K41WX6KE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82B8D206A4 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=lost-frequencies.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=wireguard-bounces@lists.zx2c4.com Received: from krantz.zx2c4.com (localhost [IPv6:::1]) by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 51dd71b8; Thu, 26 Dec 2019 15:36:46 +0000 (UTC) Received: from krantz.zx2c4.com (localhost [127.0.0.1]) by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTP id fada861e for ; Fri, 20 Dec 2019 13:47:56 +0000 (UTC) Received: from foo.lost-frequencies.eu (static.225.93.69.159.clients.your-server.de [159.69.93.225]) by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 74ff699b for ; Fri, 20 Dec 2019 13:47:56 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPA id B29695F8E1 for ; Fri, 20 Dec 2019 14:47:55 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lost-frequencies.eu; s=dkim; t=1576849675; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type; bh=gPf12mCtFuK2NLyeHO6uxThbjfAj6jtaQmQLsfXVIqI=; b=K41WX6KEXD/NfzisvVadoGMpc+31pMJqiLJUDTbXU6ktSdtNV+T6g/4f3PzGCKOLFACEyM p2DsrrLj2RD9uH3dXZHR83lUCv/o8B4R5ZoBoKRj3c+mGmUTbHgeEOLH5AHBUCe9q2oz9P 9MoSyFnIbk4mXVXEhPz20qLYV2C8Rz0= From: "google gsuite" To: wireguard@lists.zx2c4.com User-Agent: SOGoMail 4.1.1 MIME-Version: 1.0 Date: Fri, 20 Dec 2019 14:47:55 +0100 Subject: bad udp cksum messages in tcpdump for wg0 Message-ID: <49-5dfcd100-9-66d44b80@213097787> X-Mailman-Approved-At: Thu, 26 Dec 2019 16:36:40 +0100 X-BeenThere: wireguard@lists.zx2c4.com X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development discussion of WireGuard List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============7984111784936721140==" Errors-To: wireguard-bounces@lists.zx2c4.com Sender: "WireGuard" --===============7984111784936721140== Content-Type: multipart/alternative; boundary="----=_=-_OpenGroupware_org_NGMime-73-1576849675.488619-4------" ------=_=-_OpenGroupware_org_NGMime-73-1576849675.488619-4------ Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Content-Length: 978 Hi My DNS server is available via a wireguard interface. Because of many r= equests I did a tcpdump on the traffic and found messages like. 14:05:34.881307 IP (tos 0x0, ttl 63, id 33826, offset 0, flags [DF], pr= oto UDP (17), length 54) =C2=A0 =C2=A0 10.99.97.15.53628 > 10.99.97.17.domain: [bad udp cksum 0x= d719 -> 0x6360!] 8446+ A? postgres. (26) I could turn that messages off with turning off check validation on the= interface ethtool -K wg0 tx off rx off Actual changes: rx-checksumming: off tx-checksumming: off tx-checksum-ip-generic: off The tcpdump traffic looks now like this 14:08:36.494987 IP (tos 0x0, ttl 63, id 61627, offset 0, flags [DF], pr= oto UDP (17), length 54) =C2=A0 =C2=A0 10.99.97.15.40185 > 10.99.97.17.domain: [udp sum ok] 1324= + A? postgres. (26) I want to know if the behavior described above with the checksum errors= is to be expected? Or is it necessary to turn those checks off on all = the interfaces? BR ybaumy =C2=A0 ------=_=-_OpenGroupware_org_NGMime-73-1576849675.488619-4------ Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable Content-Length: 1145 Hi

My DNS server is available via a wireguard interfac= e. Because of many requests I did a tcpdump on the traffic and found me= ssages like.

14:05:34.881307 IP (tos 0x0, ttl 63, id 33826, = offset 0, flags [DF], proto UDP (17), length 54)
    10.= 99.97.15.53628 > 10.99.97.17.domain: [bad udp cksum 0xd719 -> 0x6= 360!] 8446+ A? postgres. (26)

I could turn that messages off= with turning off check validation on the interface

ethtool = -K wg0 tx off rx off
Actual changes:
rx-checksumming: off
tx-checksumming: off
tx-checksum-ip-generic: off

The = tcpdump traffic looks now like this

14:08:36.494987 IP (tos = 0x0, ttl 63, id 61627, offset 0, flags [DF], proto UDP (17), length 54)=
    10.99.97.15.40185 > 10.99.97.17.domain: [udp sum= ok] 1324+ A? postgres. (26)


I want to know if the beh= avior described above with the checksum errors is to be expected? Or is= it necessary to turn those checks off on all the interfaces?

BR
ybaumy
  ------=_=-_OpenGroupware_org_NGMime-73-1576849675.488619-4-------- --===============7984111784936721140== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ WireGuard mailing list WireGuard@lists.zx2c4.com https://lists.zx2c4.com/mailman/listinfo/wireguard --===============7984111784936721140==--