the problem

Here is my neutron issue and system setup: I have 4 servers with the following netplan configuration: https://github.com/TadiosAbebe/OSA/blob/master/network infra01.yml, compute01.yml, storage01.yml, and deploy01.yml ignore the files with _virt.yml names, I initially deployed the openstack zed release following the openstack-ansible deployment guide with linux bridges, and after successful deployment, I wasn't able to login into the Horizon dashboard with the "Something went wrong" error.

Issuing "openstack network agent list" inside the utility container results "HttpException: 503: Server Error for url: http://10.10.36.9:9696/v2.0/agents, 503 Service Unavailable: No server is available to handle this request." Looking around on the internet, I found this thread: https://bugs.launchpad.net/openstack-ansible/+bug/2002897 with the same issue, and following the suggestions there, I was able to deploy and login to the Horizon dashboard successfully. Now the problem is


1. Once in the Horizon dashboard, I can't create a network by navigating to Admin > Network > Networks > Create Network; it throws an error "Danger: An error occurred. Please try again later." So I created an external network from the utility container like this: "openstack network create --external --provider-physical-network vlan --provider-network-type vlan --provider-segment 102 public" and  "openstack subnet create --no-dhcp --allocation-pool 'start=10.20.30.100,end=10.20.30.200' --network public --subnet-range '10.20.30.0/24' --gateway '10.20.30.1' public-subnet"

2. Now instances can communicate with each other on their private addresses, i.e. 192.168.10.144 is able to ping 192.168.10.160 and vice versa, but they are not able to go out to the internet, i.e. ping 8.8.8.8. I have created a router, making the public network my external gateway.

My /etc/openstack_deploy folder resembles the following https://github.com/TadiosAbebe/OSA/blob/master/etc/openstack_deploy and I have modified the openstack_user_config.yml, user_variables.yml, ./group_vars/network_hosts, /env.d/neutron.yml and /env.d/nova.yml files. Any help or suggestions in general would be appreciated.