D-Link DI-604 - Manual (Page 16)

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HOME > WAN > DYNAMIC IP Address
Choose Dynamic IP Address to obtain IP address information
automatically from your ISP. Select this option if your ISP does not give
you any IP numbers to use. This option is commonly used for Cable
modem services.
Host Name: The Host Name field is optional but may be required by some
ISPs. The host name is the device name of the Broadband Router.
MAC Address: The default MAC address is set to the WAN's physical
interface MAC address on the Broadband Router. You can use the "Clone
MAC Address" button to copy the MAC address of the Ethernet Card
installed by your ISP and replace the WAN MAC address with this MAC
address. It is not recommended that you change the default MAC address
unless required by your ISP.