How to Clone a Mac Address to a Router

If you want to insert a NAT router between your PC and the cable modem, you might want to avoid changing the client MAC address that the cable modem connects to, for either of these reasons:
  • to avoid having to register a new client MAC address with your ISP (if your ISP is one which requires registration of the MAC address of the connected device);
  • to avoid problems with the ISP's DHCP system not immediately issuing a new IP lease when the client MAC address changes.
Many NAT routers intended for the domestic market have the ability to clone the PC's MAC address into the MAC address of the WAN port. For best effect, you should do the cloning before you first connect the router to the cable modem. To discover how to clone, please consult the documentation for your router.
For instance, the procedure for the Linksys BEFSR41 is:
  • Discover the MAC address of the PC that you want to clone.
  • Send your web browser to the Linksys configuration at and quote the password for access;Click tab Advanced;
  • Click tab MAC Addr clone;Enter the PC's MAC address, two characters in each of the six boxes.
  • Click Apply.
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