Hey, So we have created an upgrade script, which will define variables neutron_plugin_type, neutron_ml2_drivers_type and neutron_plugin_base to their prior default values in case they are undefined to /etc/openstack_deploy/user_neutron_migration.yml file: https://opendev.org/openstack/openstack-ansible/src/branch/unmaintained/zed/... So based on your reply I would suggest adding the following explicitly: neutron_ml2_drivers_type: "flat,vlan,vxlan,local" neutron_plugin_type: ml2.lxb While these missing variables should be handled by upgrade script, I'd still defined them explicitly. Also I would suggest to double check that user_neutron_migration.yml was not created before things come to upgrading neutron. On Fri, 28 Mar 2025, 15:16 Rambo Rambo, <ram.ramb2412@gmail.com> wrote:

Hi Team

We are planning openstack-ansible upgrade from Yoga to Zed.

Distribution:openstack-ansible Release: Yoga OS - Ubuntu 20.04

I was checking the release notes and can see below point related to neutron linux bridge. We are having linux bridge at the moment.

https://docs.openstack.org/releasenotes/openstack-ansible/zed.html ===========================================================

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With marking ML2/LinuxBridge driver as ‘Experimental’ in the upstream Neutron project OpenStack-Ansible has switched a default mechanism driver to ML2/OVN. In order to upgrade any existing deployment that was relying on defaults to the new OpenStack-Ansible version you must ensure that following variables are defined explicitly to ensure parity with existing functionality:

neutron_plugin_type: ml2.lxbneutron_ml2_drivers_type: "flat,vlan,vxlan,local"neutron_plugin_base: - router - metering

Failure to define any of these variables will result in playbook failures and neutron misconfiguration.

We have covered this step with upgrade script that will create a user_neutron_migration.yml file with assumed defaults.

=================================================== As per above point we need to add new parameters into user_variables file . also it is written "We have covered this step with upgrade script"

*Current Configuration:* /etc/neutron/plugins/ml2# *cat ml2_conf.ini* [ml2] type_drivers = flat,vlan,vxlan,local tenant_network_types = vxlan,flat *mechanism_drivers = linuxbridge,l2population* # ML2 flat networks extension_drivers = port_security,subnet_dns_publish_fixed_ip

*user_variable file* only has below related parameters :

neutron_l2_population: true neutron_plugin_base: - router - neutron_dynamic_routing.services.bgp.bgp_plugin.BgpPlugin

neutron_ml2_conf_ini_overrides: ml2: extension_drivers: - port_security - subnet_dns_publish_fixed_ip

Can someone please confirm what should be done to take care of above point of the release notes?

Regards