Date: Wed, 24 Oct 2012 19:00:55 +0200 From: Harald Schmalzbauer <h.schmalzbauer@omnilan.de> To: Jeremy Chadwick <jdc@koitsu.org> Cc: Adrian Chadd <adrian@freebsd.org>, FreeBSD Stable <freebsd-stable@freebsd.org> Subject: Re: every 2nd echo-request malformed when ping -s >4067 Message-ID: <50881EC7.9030400@omnilan.de> In-Reply-To: <20121024165148.GA4250@icarus.home.lan> References: <20121024154017.GA3167@icarus.home.lan> <5088163E.2090506@omnilan.de> <20121024165148.GA4250@icarus.home.lan>
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This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig71CB79B20954948157274845 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable schrieb Jeremy Chadwick am 24.10.2012 18:51 (localtime): > ... > # tcpdump -p -i em0 -l -n -s 0 -xx "icmp and dst host 4.2.2.1" > tcpdump: verbose output suppressed, use -v or -vv for full protocol dec= ode > listening on em0, link-type EN10MB (Ethernet), capture size 65535 bytes= > 09:45:22.725137 IP 192.168.1.51 > 4.2.2.1: ICMP echo request, id 6417, = seq 0, length 64 > 0x0000: e0cb 4ec0 00c4 0030 48d2 22d0=20 Have you ever seen "e0:cb:4e:c0:00:c4" and "00:30:48:d2:22:d0" ? These are your mac addresses, which -xx shows. =2E.. > And compare this to what you're seeing (look closely at the 2nd line): > > 16:03:08.963292 IP 10.5.49.126 > 10.5.49.65: ICMP echo request, id 3047= 7, seq 0, length 4076 > 16:03:09.968454 IP 10.5.49.126 > 10.5.49.65: icmp Of course, I saw that. That's why I claim the 2nd outgoing request to be malformed ;-) > ... > > This is why I said I want to see output from -xx and not -x. What I > want to see is the *full packet contents* (IP header, ICMP header, and > any ICMP payload). =20 -x gives everything above link-layer, so IP and ICMP are in my last dump.= Thanks, -Harry --------------enig71CB79B20954948157274845 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (FreeBSD) iEYEARECAAYFAlCIHscACgkQLDqVQ9VXb8h8LACglPxcdcQgiwaiI8Em3enHKObH zAkAoIlkaatp6or05i8PlZN8x3lCHmlP =XtMY -----END PGP SIGNATURE----- --------------enig71CB79B20954948157274845--
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