SMC Networks Barricade SMC2804WBR38 - Manual (Page 47)

Advanced Setup
37
Dynamic IP
The Host Name is optional, but may be required by some ISPs.
The default MAC address is set to the WAN’s physical interface
on the Router. Use this address when registering for Internet
service, and do not change it unless required by your ISP. If your
ISP used the MAC address of an Ethernet card as an identifier
when first setting up your broadband account, only connect the
PC with the registered MAC address to the Router and click the
Clone MAC Address button. This will replace the current Router
MAC address with the already registered Ethernet card MAC
address.
If you are unsure of which PC was originally set up by the
broadband technician, call your ISP and request that they
register a new MAC address for your account. Register the
default MAC address of the Router.