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SPdevotee's avatar
SPdevotee
Aspirant
Jan 19, 2021

Cm1200 single IP

I learned the problem connecting my new modem may be Comcast is only giving me 1 IP but there are 4 ports on the modem which need? Separate IPs? Suggestion on my other thread was to only use the first port.

That may get me up but then I have 3 wasted ports I can’t use and I need more output. I’m connecting to the Netgear nighthawk mesh which only has 1 Ethernet jack.

Can I configure the 4 modem ports to work off the same IP?

5 Replies

  • That is a modem/router combo.  Your ISP will only server up 1 IP address for that modem then the router will supply IP address to the other devices that you plug into the LAN ports.  

  • > I learned the problem connecting my new modem [...]

     

       What, exactly, do you believe that your "the problem" is?

     

    > [...] Comcast is only giving me 1 IP [address] [...]

     

       That would be typical for residential service.  Terminology:

     

          https://en.wikipedia.org/wiki/Internet_Protocol
          https://en.wikipedia.org/wiki/IP_address

     

    > [...] but there are 4 ports on the modem which need? Separate IPs?
    > [...]

     

       A port on the modem doesn't need an IP address.  A device which is
    connected to one of those ports does need an IP address, which it would
    get from your ISP.  Up to the number of IP addresses which your service
    agreement allows (typically one).

     

    > [...] Suggestion on my other thread was to only use the first port.


       That would be reasonable, if your service gives you only one IP
    address.

     

    > That may get me up but then I have 3 wasted ports I can't use and I
    > need more output. [...]

     

       If you didn't need those ports, then perhaps you didn't choose the
    optimum modem model.

     

       What, exactly, does "need more output" mean to you?  What, exactly,
    would you like to be able to do?  Typically, a user who has multiple
    devices will employ a NAT router to allow one external/public IP address
    to serve multiple devices.

     

       Incidentally, an Ethernet interface is bidirectional; there are no
    input ports or output ports.

     

    > [...] I'm connecting to the Netgear nighthawk mesh which only has 1
    > Ethernet jack. [...]


       Has your (unspecified) "the Netgear nighthawk mesh" a model number?
    Look for "Model" on the product label.

     

    > Can I configure the 4 modem ports to work off the same IP [address]?

     

       No.  As explained above, a modem port has no IP address.  The device
    which is connected to a modem port can have an IP address.  Typically,
    that would be the WAN/Internet port on a NAT router.  Multiple devices
    can't share that one external/public IP address.  However, the use of
    NAT allows multiple devices on your LAN (each with its own LAN IP
    address) to appear to share that one external/public IP address, as seen
    from the outside world.

    • SPdevotee's avatar
      SPdevotee
      Aspirant

      Netgear AX1800.  WIFI 6 router + 2 satellite mesh receivers.  I'm swapping this router in b/c it upgrades to WIFI 6.

       

      I was going to repurpose my current Netgear R7800 router as an access point in the living room.  

       

      There is a hard line running from my R7800 to a living room jack that then runs through a 6 port AP to feed multiple devices.  

       

      I was going to move the current AP into the computer room since I need more output from the AX1800 router (only 1 LAN port) and substitute the R7800 as the living room AP.  OR, just but another stand-alone AP.

       

      Rationalie behind using the R7800 as an AP is to also serve as a signal repeater.  Computer is on top floor, living room is below, also want to hit basement and outside with coverage.

      • FURRYe38's avatar
        FURRYe38
        Guru

        What is the model# of your NG product? RAX, RBK? Orbi? 


        SPdevotee wrote:

        Netgear AX1800.  WIFI 6 router + 2 satellite mesh receivers.  I'm swapping this router in b/c it upgrades to WIFI 6.

         

        I was going to repurpose my current Netgear R7800 router as an access point in the living room.  

         

        There is a hard line running from my R7800 to a living room jack that then runs through a 6 port AP to feed multiple devices.  

         

        I was going to move the current AP into the computer room since I need more output from the AX1800 router (only 1 LAN port) and substitute the R7800 as the living room AP.  OR, just but another stand-alone AP.

         

        Rationalie behind using the R7800 as an AP is to also serve as a signal repeater.  Computer is on top floor, living room is below, also want to hit basement and outside with coverage.