I am installing openstack using https://docs.openstack.org/install-guide/openstack-services.html (https://docs.openstack.org/install-gu...) (rocky)

I am stuck at neutron installation. I am using the https://docs.openstack.org/neutron/rocky/install/controller-install-option1-ubuntu.html (Networking Option 1: Provider networks). After all the steps and at the verification when I run : $ openstack extension list --network

I get the below error:

REQ: curl -g -i -X GET http://controllerstack:9696/v2.0/extensions -H "Accept: application/json" -H "User-Agent: openstacksdk/0.17.2 keystoneauth1/3.10.0 python-requests/2.18.4 CPython/2.7.15rc1" -H "X-Auth-Token: {SHA1}2e862b28c61bdb114ca81e4ace5c9723d4c25270"

Starting new HTTP connection (1): controllerstack Failure: Unable to establish connection to http://controllerstack:9696/v2.0/extensions (http://controllerstack:9696/v2.0/exte...): HTTPConnectionPool(host='controllerstack', port=9696): Max retries exceeded with url: /v2.0/extensions (Caused by NewConnectionError('<urllib3.connection.httpconnection 0x7ff9c5cf4e10="" at="" object="">: Failed to establish a new connection: [Errno 111] Connection refused',)). Retrying in 0.5s.</urllib3.connection.httpconnection>

I don't know what is the issue. The name of my controller is controllerstack and I have the right ip address mentioned in /etc/hosts and furthermore, I have no spelling issues in nova.conf.