Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 8 Feb 2017 12:18:14 -0800
From:      Freddie Cash <fjwcash@gmail.com>
To:        Alex Dupre <ale@freebsd.org>
Cc:        freebsd-net <freebsd-net@freebsd.org>
Subject:   Re: Multiple MAC addresses on a single interface
Message-ID:  <CAOjFWZ4jjhqEYQY9WgGVAvx-qRKSdyeiFKN6=oa2HC0HVJFyaA@mail.gmail.com>
In-Reply-To: <3e403eb2-b113-12d5-17c4-096ff32239e8@FreeBSD.org>
References:  <3e403eb2-b113-12d5-17c4-096ff32239e8@FreeBSD.org>

next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Feb 8, 2017 at 10:06 AM, Alex Dupre <ale@freebsd.org> wrote:

> Hi,
> I need to establish two PPPoE sessions on the same LAN using the same
> ethernet interface. The sessions are on different VLANs, but they are
> handled by the same AC that doesn't allow that both sessions are initiate=
d
> by the same MAC address. Is there a way to associate two MAC addresses to=
 a
> single physical interface (even by creating a virtual interface linked to
> the physical one) and so have VLANs on different mac addresses, without
> forcing the use of a secondary physical interface?


=E2=80=8BI have not tried to pass traffic over these interfaces, but it app=
ears you
can assign MAC addresses to vlan pseudo-devices:=E2=80=8B

=E2=80=8Bifconfig vlanX create
ifconfig vlanX vlan X vlandev bge0
ifconfig vlanX inet 1.2.3.4/24
ifconfig vlanX ether aa:bb:cc:dd:ee:ff

=E2=80=8Bifconfig vlanA create
ifconfig vlanA vlan A vlandev bge0
ifconfig vlanA inet 1.2.3.4/24
ifconfig vlanA ether aa:bb:cc:dd:ee:00

Here's how it looks on a live system (although without a cable plugged into
igb0).  Note the different MAC addresses for each interface.

igb0: flags=3D8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 150=
0
options=3D407bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM=
,TSO4,TSO6,LRO,VLAN_HWTSO>
ether 00:25:90:ab:20:04
nd6 options=3D29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
media: Ethernet autoselect
status: no carrier
vlan20: flags=3D8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1=
500
options=3D303<RXCSUM,TXCSUM,TSO4,TSO6>
ether 00:25:90:ab:20:14
inet 10.3.4.5 netmask 0xffffff00 broadcast 10.3.4.255
nd6 options=3D29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
media: Ethernet autoselect
status: no carrier
vlan: 20 parent interface: igb0
vlan30: flags=3D8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1=
500
options=3D303<RXCSUM,TXCSUM,TSO4,TSO6>
ether 00:25:90:ab:20:22
inet 10.3.5.6 netmask 0xffffff00 broadcast 10.3.5.255
nd6 options=3D29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
media: Ethernet autoselect
status: no carrier
vlan: 30 parent interface: igb0

=E2=80=8BWhether or not that actually works would require someone to run so=
me
tcpdumps/wireshark on the vlanX and vlanY interfaces to see what the
Ethernet frames actually look like.  :)


--=20
Freddie Cash
fjwcash@gmail.com



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAOjFWZ4jjhqEYQY9WgGVAvx-qRKSdyeiFKN6=oa2HC0HVJFyaA>