Comment 2 for bug 1546301

This does not affect MAAS 2.0, as IP allocation has been completely rewritten.

This bug occurs because the Subnet calls out to each NodeGroupInterface to determine if dynamic ranges, static ranges, cluster IP addresses, gateway IP addresses, and DNS server are reserved on the subnet.

In the case of an unmanaged subnet *without* a corresponding NodeGroupInterface, the code improperly skips values that can be determined by looking at the subnet alone (that is, gateway IP and DNS servers). These should be returned directly from the Subnet rather than going to the NodeGroupInterface.