I have a question for you about your original comments. You say your ISP knows your MAC address. If this is broadband cable you speak of - the only MAC address your ISP is concerned about is that of your cable modem. Certainly you arent trying to clone that specific MAC address into your 1710 router.
That leads me to believe that your ISP only allows you to have one CPE device. How do cable companies track that single CPE device? MAC address. The cable modem will not allow any device to pass traffic unless it is coming from that one specific CPE MAC address. There are three easy work arounds...
1. Call up your ISP, and tell them you want to pay a monthly fee for additional CPE devices. Usually they charge you $5.00 per month extra to have this luxary.
2. Every time you want to change devices to go out to the internet - plug the new device in and power cycle your modem. Every time your modem reboots, it downloads a new config file from the local QTFTP server...and reports the CURRENT CPE MAC address to the RADIUS serverices as well. The process of rebooting the cable modem over and over can get annoying, but it is sufficient if you only have like 2 PCs that you use one at a time.
3. Plug a router directly into the cable modem, and use NAT/PAT. The ISP will only see the MAC address of the router's ethernet interface, and pretty much anything behind it will be virtually "invisible".
As you can see there should be absolutely no need for cloning of anything, regardless of how many CPEs the ISP allows you to have. Perhaps you are either trying to do something that I overlooked, or your ISP is very strange. Just out of curiosity, may I ask what service provider you are using?