Comment 1 for bug 1065516

(In case it's not obvious to everyone, this is with multi_host mode)

We expect this to be regenerating the dnsmasq config:

 + # NOTE(vish): this is necessary to update dhcp
 + self.network_api.setup_networks_on_host(context,
 + instance_ref,
 + self.host)

this is called after the instance host field is updated, so you'd expect the dnsmasq config to be regenerated correctly - i.e. linux_net.update_dhcp() should be called and get_dhcp_hosts() should return the instance on the destination host but not on the source note

that code is from stable/essex and was part of the fix for bug #939060

Hard to come to any conclusions without logs. Could you attach compute and network logs from the source and destination hosts?