Hi Lokendra:

The only place I found a documented reference is [1]. If the "--provider-segment" is given to the network creation command, that will override the VLAN ranges defined per physical network in "ml2_type_vlan:network_vlan_ranges". If no pre-allocated segment is found (this process is done during the Neutron server initialization), a new one is created with the parameters the user provided [2].

Regards.

[1]https://www.oreilly.com/library/view/learning-openstack-networking/9781788392495/e0069ba3-9b46-41d3-bf4f-7520779cb38d.xhtml

[2]https://github.com/openstack/neutron/blob/db83514d052ceede559894a1439c2b45eeebe933/neutron/plugins/ml2/drivers/helpers.py#L107-L113

On Wed, May 18, 2022 at 10:22 AM Lokendra Rathour <lokendrarathour@gmail.com> wrote:

Hi Team,
We have deployed tripl0 Train using two tenant networks by configuring the parameters for additional networks.
environments.yaml:
NeutronBridgeMappings: datacentre:br-tenant,datacentre2:br-extratenant

in environments/network-environment.yaml

NeutronNetworkVLANRanges: 'datacentre:1:500,datacentre2:501:1000'

and have also isolated and separated the physical nic configuration for ovs in network/config/bond-with-vlans/compute.yaml

with this setting, overcloud is deployed and the network is getting created, Checking further, in Controller configs(/etc/neutron/plugins/ml2/) we see the changes as below, which looks fine:

[ml2_type_vlan]
network_vlan_ranges=datacentre:1:500,datacentre2:501:1000

but it is also allowing the network to be created from the wrong network segment range.
For example, while creating a network:
openstack network create --share --provider-network-type vlan --provider-physical-network datacentre2 --provider-segment 420 datacenter_2_420
-provider-physical-network- "datacentre2" is having VLAN range from 501-1000 and if I am passing the provider segment as 420(which is out of range) then also a network is getting created.

This does not look fine. please help share any inputs on the same.
--
~ Lokendra
skype: lokendrarathour