I confirm what Oleg commented: a subnet allocation pool limits the dynamic IP allocation. If a port is created without a defined IP, the IPAM module will limit the IP assignation to the allocation pool range (or ranges, a subnet can have multiple pools).
When a port is defined with an IP address, the only limitations are the existing IP addresses and the subnet CIDR.
I confirm what Oleg commented: a subnet allocation pool limits the dynamic IP allocation. If a port is created without a defined IP, the IPAM module will limit the IP assignation to the allocation pool range (or ranges, a subnet can have multiple pools).
When a port is defined with an IP address, the only limitations are the existing IP addresses and the subnet CIDR.