Hi, All I am examining notification_driver in neutron.conf. According the following link, it is used to support DHCP agent. http://docs.openstack.org/admin-guide-cloud/content/section_adv_notification_overview.html So I set neutron.openstack.common.notifier.no_op_notifier and observed neutron_dhcp_agent. But problem didn't occur (net-create/delete, subnet-create/delete, port-create/delete, boot vm). I don't know for what notification_driver is used. Is there anybody that can give me some informations about notification_driver? thanks, Hirofumi --------------------------------------------- Hirofumi Ichihara NTT Software Innovation Center Tel:+81-422-59-2843 Fax:+81-422-59-2699 Email:ichihara.hirofumi at lab.ntt.co.jp --------------------------------------------- -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack/attachments/20140606/16d82d1b/attachment.html>