Is it possible to lock down ethernet ports or lock down by MAC Address?

[NDKoze]

Is it possible to lock down ethernet ports or lock down by MAC Address?

I am trying to prevent any other device other than my main router from being able to succefully connect to the modem ethernet ports.

[FURRYe38]

What NG product model are you referring too? 

[NDKoze]

I am sorry. I thought I put that in there.

It is a CM1200 Nighthawk® Multi-Gig Cable Modem

[FURRYe38]

This is a modem only. No built in router here. 

[NDKoze]

I understand that. But, the modem has 4 ethernet ports on it and I want to know if it is possible to lock them down either totally or by MAC Address.

I only want my one Netgear Router to be attached to the modem and work.

[Kitsap]

In general, the only port on the back of your CM1200 that is active is port 1.  Port 2 can be activated for a Link Aggregation (LAG) connection.  LAG can be activated from the modem user interface.  Ports 3 and 4 are active only from limited service providers that can provide more than one IP address for a modem.

Out of the box, ports 2 through 4 should have had a blank black plug installed.  There are more details in the user manual and setup guide.  They can be downloaded from the Downloads section at the top of the page.

[FURRYe38]

The ports are WAN side ports thus assigned by an ISP that, if they support giving more than one WAN side IP address to the modem, then these ports could be active. Otherwise they are not active or lockable, unless you enable LAG on the modem to connect to a external router that also supports LAG on it's WAN side as well. 

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@NDKoze wrote:

I understand that. But, the modem has 4 ethernet ports on it and I want to know if it is possible to lock them down either totally or by MAC Address.

I only want my one Netgear Router to be attached to the modem and work.

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