Address Assignment With Dhcp - Siemens SCALANCE XB-200 Configuration Manual

● CLI via the serial interface
For further information on assigning the IP address using the CLI, refer to the
documentation "SCALANCE XB-200/XC-200/XP-200 Command Line Interface".
● NCM PC
For further information on assigning the IP address using NCM PC, refer to the
documentation "Commissioning PC stations - Manual and Quick Start", in the section
"Creating a PROFINET IO system".
Note
When the product ships and following "Restore Factory Defaults and Restart", DHCP is
enabled. If a DHCP server is available in the local area network, and this responds to the
DHCP request of an IE switch, the IP address, subnet mask and gateway are assigned
automatically when the device first starts up.
3.3

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:
● DHCP can be used both when starting up a device and during ongoing operation.
● The assigned IP address remains valid only for a limited time known as the lease time.
When half the period of validity has elapsed. the DHCP client can extend the period of
the assigned IPv4 address. When the entire time has elapsed, the DHCP client needs to
request a new IPv4 address.
● If the device does not reach the DHCP server with a new request on expiry of the lease
time, the assigned IP address, the subnet mask and the gateway continue to be used.
The device therefore remains accessible under the last assigned IP address even without
a DHCP server. This is not the standard behavior of office devices but is necessary for
problem-free operation of the plant.
● 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
possible to configure the DHCP server so that the DHCP client always receives the same
fixed address in response to its request. The parameter with which the DHCP client is
identified for the fixed address assignment is set on the DHCP client and server. The
address can be assigned via the MAC address, the DHCP client ID, the PROFINET or
the system name. You configure the parameter in "System > DHCP > DHCP Client".
SCALANCE XB-200/XC-200/XP-200 Web Based Management
Configuration Manual, 07/2016, C79000-G8976-C360-04
Assignment of an IP address
3.3 Address assignment with DHCP
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