Configuration / project engineering
5.2 Assignment of an IP address
SCALANCE W786-xPRO
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Operating Instructions, Release 08/2007, C79000-G8976-C221-02
5.2.2
Initial assignment of an IP address
Configuration options
An initial IP address for a SCALANCE W-700 cannot be assigned using Web Based
Management or the Command Line Interface over Telnet because these configuration tools
require that an IP address already exists.
The following options are available to assign an IP address to an unconfigured device
currently without an IP address:
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DHCP (default)
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STEP 7
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NCM PC
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Primary Setup Tool
Note
DHCP is enabled as default and following "Restore Factory Defaults and Restart". If a DHCP
server is available in the local area network, and this responds to the DHCP request of a
SCALANCE W-700, the IP address, subnet mask and gateway are assigned automatically
when the device first starts up. "Reset to Memory Defaults" does not delete an IP address
assigned either by DHCP or by the user.
5.2.3
Address assignment with DHCP
Properties of DHCP
DHCP (Dynamic Host Configuration Protocol) is a method for automatic assignment of IP
addresses. It has the following characteristics:
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DHCP can be used both when a device starts up and during operation.
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The assigned IP address remains valid only for a particular time known as the lease time.
Once this period has elapsed, the client must either request a new IP address or extend
the lease time of the existing IP address.
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There is normally no fixed address assignment; in other words, when a client requests an
IP address again, it normally receives a different address from the previous address. It is,
however possible, to configure the DHCP server so that it assigns a fixed address.