Comment 1 for bug 1451559

You should think of the first subnet create as creating a subnet from a special pool. We've called that pool the "implicit", "null", "unnamed", or "default" pool over time. Regardless of the name, it is the pool that existed in Neutron before the subnet pool feature came to be.

The second subnet-create comes from a different pool, the one you named "pool". So, this bug gets in to what happens when we mix addresses from two different pools on the same network. Allocations from two different pools will never be checked for overlap.

I had thought about disallowing this but it didn't fit in the scope for Kilo. For now, please be advised that all subnets on the same network should come from the same pool until we can work out if and how it can work.

We should probably address this bug report by checking that all subnets on a network come from the same pool.