Date: Wed, 1 Jan 2014 19:57:21 +1100 From: Peter Jeremy <peter@rulingia.com> To: freebsd-net@freebsd.org Subject: IPv4 Multicast MAC Address issues Message-ID: <20140101085721.GA34334@server.rulingia.com>
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--IJpNTDwzlM2Ie8A6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable I'm trying to use multicast on my home network for the first time and have found an apparent anomoly in the destination MAC address. My reading of RFC1112 section 6.4 is that the the destination MAC address uses the low 23 bits of the destination (multicast) IP address. This is what Linux and Windows do and ifmcstat(8) on FreeBSD shows that as the multicast MAC filter. Unfortunately, it seems that (at least on FreeBSD-10), the destination MAC address uses the low 23 bits of the IP address of my default route. I am not doing any special multicast-related configuration on any of the hosts and have been using ping(8) to generate multicast packets. Does FreeBSD need special configuration to support multicast or is this a bug? --=20 Peter Jeremy --IJpNTDwzlM2Ie8A6 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (FreeBSD) iKYEARECAGYFAlLD2HFfFIAAAAAALgAoaXNzdWVyLWZwckBub3RhdGlvbnMub3Bl bnBncC5maWZ0aGhvcnNlbWFuLm5ldDBCRjc3QTcyNTg5NEVCRTY0RjREN0VFRUZF OEE0N0JGRjAwRkI4ODcACgkQ/opHv/APuId8KACfcedqTHKmw7FD8iqMTOkc/XKe gdEAnRCKv9LSbWNp+r4fMRhQbOVmfKTI =8tEW -----END PGP SIGNATURE----- --IJpNTDwzlM2Ie8A6--
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