以下是官方给的英文版
You can manage the subnet using the 'Network' tab. Click on manage option there next to the subnet assigned to the server. In KVM platform, you need to use 'Reconfigure Networking' option from the Home screen of the control panel and wait to complete the reconfigure and a server reboot.
The added IP's can be viewed and removed from there but the reconfigure option is also needed here in order to take effect the removals as well.
You can set rDNS for the IP's by clicking 'Edit' option there next to each IP's you have added, no reboot is needed there.