[Openstack] ARP packets not sent during migration
yes, you're right, that's the point, libvirt is sending gARPs too
early.... am I misconfiguring something? Seems to me a really strange
Il 21/03/18 22:35, Brian Haley ha scritto:
> On 03/20/2018 12:40 PM, Ramon Orru wrote:
>> Hello everybody, I'm running a fresh queens cluster. I'm using
>> bridges to support networking. I'm facing an issue when an instance
>> is live migrated.
>> Suppose we have an instance running with an interface on vlan XXX,
>> and we want to migrate it to compute host YYY. We'll call that
>> instance ZZZ.
>> If no other instance is already running on YYY using vlan XXX, no
>> bridge called 'br-vlan.XXX at br-vlan' exists yet on YYY.
>> Now, if I migrate ZZZ on YYY host, a new bridge 'br-vlan.XXX at br-vlan'
>> will be created.
>> During the migration process, ZZZ become unreachable while interfaces
>> are going up on YYY (from 10 seconds to about 2 minutes).
>> After some troubleshooting, we spotted the problem: bridge
>> 'br-vlan.XXX at br-vlan' is being created after gratuitous ARP packets
>> are sent from migrating machines to advise other devices about new
>> The result is: no other device can reach the fresh migrated machine
>> until ARP table becomes stale.
>> This does not happen when an instance with an interface on same vlan
>> is already runnning on destination host ('br-vlan.XXX at br-vlan' is
>> already up and running, and ARPs can be sent flawlessly).
>> Any idea of how to get rid of this? I think it's very unlikely that
>> I'm the first to face this problem, but i didn't manage to find
>> additional info on this strange behaviour.
>> Thanks in advance.
> Just to clarify - are you talking about connectivity to the floating
> IP or just on the VLAN itself, i.e. the instance is directly connected
> to the VLAN.Â I'm thinking it's the latter, which would mean it's
> libvirt(?) sending the gARPs before the bridge is up?