Hello. I come back to you to try to understand my problem. My installation is based on kolla-ansible, Yoga, Centos-Stream. For some time, without understanding why, neutron_dhcp no longer works on external networks and the networks of my students' projects. This generates many error messages, which are difficult to understand. Could this be a bug in this version? Before, it worked very well, but I have the impression that when the number of network increases (i’m not sure), from a moment, dhcp does not work anymore. What is the way to find the problem? Here are examples of errors that won't stop even if no one creates more instances of them 2023-04-04 20:36:52.870 7 ERROR neutron.agent.dhcp.agent device, namespace, scope, broadcast) 2023-04-04 20:36:52.870 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/oslo_privsep/priv_context.py", line 272, in _wrap 2023-04-04 20:36:52.870 7 ERROR neutron.agent.dhcp.agent r_call_timeout) 2023-04-04 20:36:52.870 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/oslo_privsep/daemon.py", line 215, in remote_call 2023-04-04 20:36:52.870 7 ERROR neutron.agent.dhcp.agent raise exc_type(*result[2]) 2023-04-04 20:36:52.870 7 ERROR neutron.agent.dhcp.agent neutron.privileged.agent.linux.ip_lib.InvalidArgument: Invalid parameter/value used on interface tap73cd30e2-35, namespace qdhcp-395f1edb-de6d-4dd8-b31b-69a53780c012. 2023-04-04 20:36:52.870 7 ERROR neutron.agent.dhcp.agent 2023-04-04 20:36:52.871 7 INFO neutron.agent.dhcp.agent [-] Finished network 395f1edb-de6d-4dd8-b31b-69a53780c012 dhcp configuration 2023-04-04 20:36:52.872 7 INFO neutron.agent.dhcp.agent [-] Starting network 8db375e0-28d2-4379-9330-397dc9b4f2b1 dhcp configuration 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent [-] Unable to enable dhcp for 8db375e0-28d2-4379-9330-397dc9b4f2b1.: neutron.privileged.agent.linux.ip_lib.InvalidArgument: Invalid parameter/value used on interface tap1c220d25-b9, namespace qdhcp-8db375e0-28d2-4379-9330-397dc9b4f2b1. 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent Traceback (most recent call last): 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/neutron/agent/dhcp/agent.py", line 218, in call_driver 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent rv = getattr(driver, action)(**action_kwargs) 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/neutron/agent/linux/dhcp.py", line 274, in enable 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent common_utils.wait_until_true(self._enable, timeout=300) 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/neutron/common/utils.py", line 717, in wait_until_true 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent while not predicate(): 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/neutron/agent/linux/dhcp.py", line 286, in _enable 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent interface_name = self.device_manager.setup(self.network) 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/neutron/agent/linux/dhcp.py", line 1779, in setup 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent namespace=network.namespace) 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/neutron/agent/linux/interface.py", line 152, in init_l3 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent device.addr.add(ip_cidr) 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/neutron/agent/linux/ip_lib.py", line 537, in add 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent add_broadcast) 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/neutron/agent/linux/ip_lib.py", line 823, in add_ip_address 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent device, namespace, scope, broadcast) 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/oslo_privsep/priv_context.py", line 272, in _wrap 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent r_call_timeout) 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent File "/var/lib/kolla/venv/lib/python3.6/site-packages/oslo_privsep/daemon.py", line 215, in remote_call 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent raise exc_type(*result[2]) 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent neutron.privileged.agent.linux.ip_lib.InvalidArgument: Invalid parameter/value used on interface tap1c220d25-b9, namespace qdhcp-8db375e0-28d2-4379-9330-397dc9b4f2b1. 2023-04-04 20:36:53.587 7 ERROR neutron.agent.dhcp.agent Thanks a lot Franck