Select the Addresses tab.
Choose Delete Networks from the Edit menu.
The Delete Networks dialog box opens.
In the Keep Networks list, select the networks you want to delete.
Press the Control key while you click with the mouse to select multiple networks, or press the Shift key while you click to select a range of networks.
Click the right arrow button to move the selected networks to the Delete Networks list.
If you want to remove the host table entries for the DHCP–managed addresses on this network, select Delete Host Table Entries.
Note that this does not delete the host registrations at the DNS server for these addresses. It affects only the local name service.