Technical basics
3.2 MAC address
SCALANCE SC-600 Web Based Management (WBM)
Configuration Manual, 10/2021, C79000-G8976-C475-03
37
•
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. The address can be assigned via the MAC address, the DHCP client ID or the
device name. You configure the parameter in "System > DHCP Client (Page 156)".
•
The following DHCP options are supported:
–
DHCP option 1: Assignment of a subnet mask
–
DHCP option 3: Assignment of a router address
–
DHCP option 6: Assignment of a DNS server address
–
DHCP option 15: DNS domain name
–
DHCP option 12: Assignment of a host name
–
DHCP option 66: Assignment of a dynamic TFTP server name
–
DHCP option 67: Assignment of a dynamic boot file name
Note
DHCP uses a mechanism with which the IP address is assigned for only a short time
(lease time). 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.
3.2
MAC address
Note on the structure of the MAC address:
MAC addresses are hardware addresses for identifying network nodes. A MAC address
consists of six byes separated by hyphens in hexadecimal notation.
The MAC address consists of a fixed and a variable part. The fixed part ("basic MAC
address") identifies the manufacturer (Siemens, 3COM, ...). The variable part of the MAC
address distinguishes the various Ethernet nodes.
Summary of Contents for SIMATIC NET SCALANCE SC-600
Page 68: ......