Siemens CP 1515 User Manual page 273

A dynamically assigned IP address is referred to as an ' A ctive Lease' .
The Active Lease usually has an expiry date, which allows re-
allocation of IP addresses that are no longer used.
For Radio Link Modules you are advised to use a specific IP address
for which there is no expiry date. To do so, you can use your DHCP
management program to reserve the IP address or a range of IP
addresses.
For network devices that require a specific IP address, or for which
you do not want the 'IP address lease' to expire, you can use a DHCP
Management program to reserve their IP addresses. This is the case
with your Radio Link Modules.
Once a range of IP addresses has been reserved, you can use the
values in this range to assign to your SIMATIC NET IWL system.
The Unique Identifier is the Media Access Control (MAC) address for
the DHCP Client. The Client Name should be the computer name for
the DHCP Client. However, this name is used for identification
purposes in the DHCP Manager interface and, therefore, does not
have to be and will not affect the actual computer name.
To see which IP addresses are still available, your DHCP Management
program will usually include a 'Scope Active Leases' option. This
option allows you to see which DHCP Clients have leased an IP
address from the DHCP Server.
Industrial Ethernet Wireless LAN RLM Manager, CP 1515 Manager
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