You can use this operation to update information for a port, such as its symbolic name and
associated IPs. When you update IPs for a port, the previously associated IPs are removed,
returned to the respective subnets allocation pools, and replaced by the IPs specified in the
body for the update request. Therefore, this operation replaces the fixed_ip attribute
when it is specified in the request body. If the new IP addresses are not valid, for example,
they are already in use, the operation fails and the existing IP addresses are not removed
from the port.