FUEL can check if ip addresses are busy (for management, storage and public networks)

FUEL must check ip addresses (if they are available) before assign them to the nodes. It can solve a lot of networks troubles with minimum efforts.
Sometimes during the deployment some ip addresses can be already assigned to switches or routers and deployment engineer often don't know about it until he get connectivity troubles later.
On the other hand FUEL can't specify ip ranges (only CIDR) for Management and Storage and smart ip assigning would be useful for deployment where we don't want to use begining or ending of subnets.

I see two options:

 - Smart ip assigning (We can check if ip address is available (by broadcast ARP) before assign the address on the node during deployment)
 - Verify Network (We can scan all the subnets during network verification and then show errors about assigned IP, or just avoid using ip addreses that are assigned)