The overcloud heat stack create fails with: [overcloud]: CREATE_FAILED The Referenced Attribute (Networks ('net_attributes_map', 'ctlplane', 'subnets', 'ctlplane-subnet', 'cidr')) is incorrect. This is due to a nested get_attr used in the VIP resources. Heat does not correctly add implicit depends_on in this case. It happens to work for a regular deployment but fails for multistack deployments such as DCN.
Resolved in 17.1