Date: Mon, 6 Feb 2017 19:53:48 +0100 From: Giulio Ferro <auryn@zirakzigil.org> To: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, freebsd-hackers@freebsd.org Subject: Duplicate MAC addresses in VNET epair interaces Message-ID: <472069af-0f9d-d830-064b-2d984a5774ae@zirakzigil.org>
next in thread | raw e-mail | index | archive | help
Hi all,
Setup:
11.0-STABLE FreeBSD 11.0-STABLE #0 r312338: Tue Jan 17 12:29:38 UTC 2017
I've set up two freebsd hosts, each of which has a single VNET jail.
On each host I've created 2 epair interfaces.
Host A
- epair0a, epair1a on the host
- epair0b, epair1b on the jail
Host B
- epair0a, epair10a on the host
- epair0b, epair10b on the jail
What I noticed is that on both hosts, each epair interface has the same
MAC address:
Host A:
root@xxx:~ # ifconfig epair0a
epair0a: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu
1500
options=8<VLAN_MTU>
ether 02:ff:e0:00:03:0a
inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
status: active
groups: epair
root@xxx:~ # ifconfig epair1a
epair1a: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST>
metric 0 mtu 1500
options=8<VLAN_MTU>
ether 02:ff:e0:00:05:0a
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
status: active
groups: epair
Host B:
root@yyy:~ # ifconfig epair0a
epair0a: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu
1500
options=8<VLAN_MTU>
ether 02:ff:e0:00:03:0a
inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
status: active
groups: epair
root@yyy:~ # ifconfig epair10a
epair10a:
flags=28943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST,PPROMISC>
metric 0 mtu 1500
options=8<VLAN_MTU>
ether 02:ff:e0:00:05:0a
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
status: active
groups: epair
(same behavior on the epair interfaces on the jail side)
As you can see, the mac addresses seems to depend on the order of the
creation of the epair, not on the name or address
This is a potentially bad behavior, because if I want to bridge say
epair1a on A with epair10a on B with a VPN or
a physical connection giving 192.168.1.1 to epair1b and 192.168.1.2 to
epair10b, I won't be able to make them
talk to each other since they have the same MAC address.
My question is: is this a bug or something I'm doing wrong? If there any
workaround I can use?
Thanks
Giulio
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?472069af-0f9d-d830-064b-2d984a5774ae>