Comment 2 for bug 1602482

All IPs that are valid (as in have been assigned and not expired) are given interface.fqdn names, unless they are the fqdn choice ("best IP" from get_hostname_ip_mapping -- generally pxeboot interface assigned/static/whatever IP.)

The reported behavior is consistent with the DHCP lease used in commissioning being valid after commissioning finishes (no release at the end of commissioning.)

The quick fix is to use a shorter lease time in maas-dhcp, the more complete fix is to change the commissioning process to actively release the DHCP IP at the end.