It is strictly meant for Internal use only. The IP's your computers recieve, 192.168.1.xxx are known as Private IP addresses, and are not routeable in the outside world. With this IP address anyone in the world can talk to your Netgear router while your Cable Modem acts as the bridge. The 66. IP address you see is known as a Public IP Address and is the IP known to the world.
Now that we've got down that part, let me answer your question if I haven't already. It accomplishes this function by providing IP Address in a different range and automatically takes care of all the transactions for you automatically. This allows it to distrubute one single IP Address from your ISP for all devices that connect to the router. Your Netgear Router has a function called NAT (Network Address Translation). When you hook up your Netgear Router behind the Cable Modem, then the Cable Modem acts as a Bridge between your ISP and your Netgear Router allowing all traffic to pass through.Ĥ. It is not used for any Internet based traffic.ģ. What that allows is for the Cable Modem to come online and revieve an IP address used for local purposes only. When you are given a Cable Modem it has to be provisioned with a certain package/speed based upon the HFC Mac Address on that Cable Modem.Ģ. Your in luck as I work for a Cable Company and run this type of setup.ġ. Wouldn't the first thing the cable company and outside world sees be the IP (and MAC) address for the modem itself, or are these values masked, and does the cable company see the MAC and IP address from the router's WAN side instead. However, when I go to a site like it gives me the dynamically assigned IP address for the WAN side of the router. In this case, the packet would start at my computer, hop to the internal side of the router, hop to the external side of the router, and then hop to the modem, then out the cable to the next router. I guess what I am confused most about is that I thought packets "hop" from place to place. I'm assuming the cable company authenticates the account with this MAC address? If the modem has a MAC address, wouldn't it also need its own IP address that is dynamically assigned and separate from the one that was dynamically assigned to the router's WAN side? Why is this the case?Īlso, the modem itself has its own MAC address stamped on the underside.
68.72.123.21) Often the last two octets change, depending on if I use the modem or router directly. I mean a different WAN address like 68.72.124.47. (I am not talking about an internal address like 192.168.1.3. In this case, the ISP assigns a different IP address if I plug my computer directly into the modem than if I plug it into the router.
(The hexadecimal values are the same, except for the rightmost one.) I understand the need for this, and it would be much less confusing if the device was a combination router/modem. It has two separate MAC addresses for the internal private LAN side and the public WAN side. I have an external Comcast cable modem hooked up to a separate Netgear wireless router. I am probably needlessly complicating a simple question. I apologize in advance for the length of this message.