[libvirt-users] Guests can't connect to each other

[Laine Stump]

On 04/13/2012 03:17 PM, Richard W.M. Jones wrote:
> On Fri, Apr 13, 2012 at 02:33:24PM +0200, Anthony Bourguignon wrote:
>> Hi,
>>
>> I'm using libvirt and qemu on Debian Wheezy. I'm having a strange
>> behavior. Guests can't connect to each other when they're on the same
>> host.
>>
>> On the host I'm using bonding (in active / backup mode) and vlan. It
>> looks like this :
>> eth0 \                / macvtap0
>>      bond0 --- vlan222
>> eth1 /                \ macvtap1
> I thought it was a known problem that macvtap guests can't
> talk to each other ...?

guests can't talk directly to the *host*. They can talk to each other
though, as long as "bridge" mode is uses. In "private", "vepa" and
"passthrough" modes, *all* traffic goes only out to the switch, so any
communication between guests must be via the switch (and if the switch
doesn't support that, they can't talk).