Re: vlans + bridging is "interesting"

> Hello,
> 
> I decided to try to run some bhyve VM's on my machine and bridge
> them to a guest vlan on my main interface.  I also want to support
> running bhyve VM's on the untagged part of the interface as well
> (this is the key problem as I'll describe later).
> 
> I configure it as you'd expect.  Bridge the main interface em0, and
> put the local IP's on the bridge0.  Then I added an interface em0.14
> that untags packets from em0, and added it to bridge1 along w/ a tap0
> for the VM.  This does not work.  Packet goes out and comes back and
> is observed on em0, but never appears on either em0.14 or bridge1.
> 
> After seeing: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=139268
> 
> I decide to look on bridge0, and see the tagged vlan packet on that
> interface.  I attempted to add bridge0 as the vlandev for em0.14, but
> that doesn't work:
> #ifconfig em0.14 vlan 14 vlandev bridge0
> ifconfig: SIOCSETVLAN: Protocol not supported
> 
> So, I did finally get things working by using epair.  I added an epair
> to the bridge, and that allows me to untag the packet, and pass on to
> bridge1.
> 
> I have not attempted to use the patch in 139268, but if people think
> it is an acceptable solution (with patch, if I set LINK0, it should work
> w/ original configuration), I'll test and commit the patch.
> 
> Otherwise, please submit another fix.
> 
> Thanks.

I am also experiencing difficulties with vlan +briding +bhyve.  It
seems the host that can talk just fine out a trunked em0 interface
using vlan32 and vlan34 to all my other hardware can NOT talk to
my bhyve guests.  Those bhyve guests can also talk out that
same interface to other hardware, but they are being passed in
the trunked interface, ie direct tap of bridge of em0 and the
vlan tagging/untagging is being done inside the guest.

All the guests can talk to each other and they can all talk
to real hardware that is via the em0 hardware, same for the
host, but the host can not talk to the guests nor the guests
to the host.

My guess is that the arp's are not being seen by the bridge
cause they are wrapping in vlan tags thus the bridge
never learns all the mac addresses, but this is just a
guess.

-- 
Rod Grimes                                                 rgrimes_at_freebsd.org