On Tue, 26 Jan 2016 01:23:40 +0100, Melzzzzz wrote:

Seems that Comcast is lying...

I'm slowly coming to the realization that Comcast is the guilty party here.

Looking at this web page, it seems that Comcast might be requiring *two*
different MAC addresses.

http://homepage.ntlworld.com/robin.d....html#macclone

That page says:
"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:
1. 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);
2. 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.

If the router had already been connected to a cable modem, then after
cloning a new MAC address into the WAN port, you must perform the
procedures of Swapping computers on the cable modem.

With the cloned MAC address in the router's WAN port, then as far as
the cable modem is concerned, it is talking to the original PC.

So, it seems that Comcast is the guilty culprit, because Comcast is
*requiring* (it seems) two exact MAC addresses:
a. One (real) MAC for the DOCSIS3 modem, and,
b. Another (bogus) MAC for the "computer" that connects to the modem.
(Where this "computer" is the router itself.)

Is that correct yet?