Openstack - Add multiple IPs to one port

Currently I have setup an instance with one interface and a vip with keepalived. Communication to the primary interface is working but not to the vip. I have tried adding an additional port with the ip address but with no luck. Below is what I have tried and the error. (192.168.1.50 - is the vip)

openstack port create --network l_network --fixed-ip subnet=10990c09-5893-4r68-ecre-307ed7740ey6,ip-address=192.168.1.50 --mac-address=fb:17:3d:a6:08:37 port1

Unable to complete operation for network f6601b8f-dhb2-4567-t399-124fb5hd8895. The mac address fb:17:3d:a6:08:37 is in use.

I managed to get it working by creating an additional port and then linking it to the Openstack Instance

Create the port for VIP

neutron port-create --fixed-ip subnet_id=<subnet_id>,ip_address=192.168.1.50 --no-security-groups --name "vip" <id_of_net>

to find id of subnet and network id:

neutron net-list

link the port to the instances:

neutron port-update <port_id_of_current_instance> --allowed-address-pairs type=dict list=true ip_address=192.168.1.50

to find the port_ids:

neutron port-list