Managing The Database - Novell NETWARE 6-DOCUMENTATION Manual

Managing the Database

Table 3
IP Assignment Policy
Delete Duplicate
Allow Duplicate
No Duplicate
42
Novell DNS/DHCP Management Utility Administration Guide
The Lease Time attribute of the Subnet object enables a dynamic DHCP client
to specify a lease time for the entire subnet. Lease expiration time can be
modified for each manual IP address allocation.
An IP address can be returned to a DHCP server for one of the following
reasons:
The address is explicitly released by a DHCP client.
The address is implicitly released because the lease has expired.
An assigned lease is canceled by the DNS/DHCP Management Utility.
If a DHCP client requests an IP address on the same subnet again before the
previously assigned address expires, the same address is provided. If the IP
address assignment is for a different subnet but the client already has a valid
IP address entry in the DHCP server database, three possible actions can
occur, depending on the IP Address Assignment Policy attribute of the DHCP
server. The three possible actions are listed in
IP Address Assignment Policy
DHCP Server Action
If the client moves to another subnet supported by the same DHCP server,
delete any previous IP address assigned to the client, release the original
address back to the pool, and assign a new address.
If the client moves to another subnet, assign the new address and leave the
old address unchanged in the database.
If the client moves to another subnet and the old address is still valid, do not
assign a new address.
The address deletion might delete a permanent IP object that is dynamically
or manually assigned. Therefore, a client with a Delete Duplicate policy can
have a walking manual IP object, but it cannot walk out of the service scope
of a single DHCP server. For a DHCP server to assign an address to a walking
manual IP object, the address assignment must be from a DHCP server's
reserved Subnet Address Range with Range Type set to Dynamic DHCP,
Dynamic BOOTP and DHCP, or Dynamic DHCP with Automatic Hostname
Generation.
Table 3.