[Users] users quota and limit ips

Hi all, we are wondering how can we limit a user to use IPs we give him and not others. Best is understood from an example: - we give a user a quota (with x CPU, y memory and z disk space) - a user can create one VirtualMachine with all the resources, or more VirtualMachines with smaller resources. - we want to give a user a pool of IPs. He should not use other IPs. If he uses other IP it should not be routable. Is there a solution for this problem? Thank you. Best Regards, Andrej Bagon Arnes