From owner-freebsd-net@freebsd.org Wed Mar 6 11:46:02 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 AC2A6150E8E3 for ; Wed, 6 Mar 2019 11:46:02 +0000 (UTC) (envelope-from meka@tilda.center) Received: from mail.tilda.center (srv02.tilda.center [199.247.21.11]) by mx1.freebsd.org (Postfix) with ESMTP id 738CD899F1 for ; Wed, 6 Mar 2019 11:46:01 +0000 (UTC) (envelope-from meka@tilda.center) Received: from hal9000.home.meka.rs (178-223-64-96.dynamic.isp.telekom.rs [178.223.64.96]) by mail.tilda.center (Postfix) with ESMTPSA id ECDB117F74; Wed, 6 Mar 2019 12:45:58 +0100 (CET) Date: Wed, 6 Mar 2019 12:45:59 +0100 From: Goran =?utf-8?B?TWVracSH?= To: Eugene Grosbein Cc: freebsd-net@freebsd.org Subject: Re: UDP broadcast Message-ID: <20190306114558.yjci5benmnsazrun@hal9000.home.meka.rs> References: <20190305224610.frw5ov5bn6f3xaqg@hal9000.home.meka.rs> <149e7a2f-6297-3478-e8c0-64baeeb02d8b@grosbein.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="kk3xj37ngyizhqjj" Content-Disposition: inline In-Reply-To: <149e7a2f-6297-3478-e8c0-64baeeb02d8b@grosbein.net> User-Agent: NeoMutt/20180716 X-Rspamd-Queue-Id: 738CD899F1 X-Spamd-Bar: ------- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of meka@tilda.center designates 199.247.21.11 as permitted sender) smtp.mailfrom=meka@tilda.center X-Spamd-Result: default: False [-7.88 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.20)[multipart/signed,text/plain]; DMARC_NA(0.00)[tilda.center]; TO_MATCH_ENVRCPT_SOME(0.00)[]; MX_GOOD(-0.01)[cached: mail.tilda.center]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_SHORT(-0.82)[-0.822,0]; SIGNED_PGP(-2.00)[]; RCVD_NO_TLS_LAST(0.10)[]; RECEIVED_SPAMHAUS_PBL(0.00)[96.64.223.178.zen.spamhaus.org : 127.0.0.11]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+,1:+]; ASN(0.00)[asn:20473, ipnet:199.247.16.0/21, country:US]; RCVD_COUNT_TWO(0.00)[2]; IP_SCORE(-2.74)[ip: (-9.53), ipnet: 199.247.16.0/21(-4.63), asn: 20473(0.51), country: US(-0.07)]; FROM_EQ_ENVFROM(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: Wed, 06 Mar 2019 11:46:02 -0000 --kk3xj37ngyizhqjj Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Mar 06, 2019 at 03:52:31PM +0700, Eugene Grosbein wrote: > 06.03.2019 5:46, Goran Meki=C4=87 wrote: > As shown, nc generates UDP datagramm without (optional) checksum. It's because of offloading. When I check it on router, checksum is fine. > > So what am I doing wrong and how can I send UDP broadcast from either s= cript of C code? Thank you! > > You should try ncat from security/nmap instead of nc. Tried it with this: printf "/info\0\0\0" | ncat -4u 255.255.255.255 10024 Absolutely same result. If I use mixer IP I get the response, so I know what I'm sending is OK: printf "/info\0\0\0" | ncat -4u 192.168.5.80 10024 It works with ncat and nc. Regards, meka --kk3xj37ngyizhqjj Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEE1WIFkXy2ZeMKjjKEWj1TknovrLYFAlx/svQACgkQWj1Tknov rLa7pw//SxAl/SHPNAuIYrgZYyKq9Di5PQ1Dxt3k0mI4qMvWfdgwPzeUk781xBDK zIudjy5XkNbEtDSThdVDi4Bl1VJY6b4rsYv8XdIyg1cS+MA2pP43PLLmW7byzx7b w+c704YAbaSuA7ygrGcTnGNFdOkPTJUIoz1jeWZVfywKvww26TT58VLWFp9AC/C7 eORx7bEU0gIR7mNme2vR87mLQyj/JWag9kbGWjIQJMl8pzvB2ggXagEGUHIY0Ac8 wxKn3LgpCc5mMONnIzNMxrLsOOaNDCRulMlA7O+Pyhf7+XW2ABMrZTA7gFqPP48z y11zLem5vdxTirx9sQfPZoIus0Owab0hwXYlWDHczgbVci/t0T3sfcNw2tyIFslU O1jYR0gjMWRCe1fP7AugKAjpYuqKEPMJK70cIi25t/taF4E3IHPKBCIc9NoRzwW9 k8C9SD3zOnbFeEha54GYdYUTtAWtdBGI8U9cUS4dXH9mcRTWi5fELjFlsJczlZgo 7YPs5CI00o8YcWugI4lL6R4Twn6D6tiZuYvKhBVz6qyUBVgPSC2e8J7zuOL9wVOC rAL05RCs7uJPdqwLIIAVxUWTu/cFcu6V+UKnfg6JuTisEY4Av7oHLbHL7AkWjNq+ bw8sKjRReESvROiEy1RJvnLo8KLIXA62vcrKcNwmZtFrgw82D7U= =wXmD -----END PGP SIGNATURE----- --kk3xj37ngyizhqjj--