I bought a CM1000 from Best Buy this afternoon. This is to replace a Motorola cable modem I've had for a number of years with something faster. After a bunch of fooling around with Comcast the CM1000 is talking to their network. It is not, however, talking to my network. The only exception is if I connect a laptop directly to the CM1000. The Ethernet light is red unless only a single computer is connected. Not acceptable. Any ideas before I take this thing back to Best Buy? Netgear's support stinks as it is only available during certain hours and they want "Proof of Purchase", which downloads from Comcast in a format that this website will not accept.

> [...] After a bunch of fooling around with Comcast [...] Not much meat on that bone.> [...] It is not, however, talking to my network. [...] And how would it do that? Through some (unspecified, secret(?))router or other?> [...] The Ethernet light is red unless only a single computer is> connected. [...] Any "a single computer", or one specific "a single computer"? https://community.netgear.com/t5/x/x/m-p/1574972

Snarky replies aren't very helpful... "talking to my network" means just what you suppose it means - through the Ethernet connection. Connect it to either router or the switch and you get a red light. Connect the cable modem directly to the laptop I'm using and you get a green light. Red light = no joy in communicating with anything over Ethernet.

> Snarky replies aren't very helpful... Not answering specific questions is what's really unhelpful in thesesituations. Along with information-free problem descriptions.> [...] Connect it to either router or the switch and you get a red> light. Still wondering what that mysterious "router" might be, And what is your "the switch"? Connecting a modem directly to anetwork switch would very likely cause trouble with multiple clientdevices. Why involve it, whatever it is?> [...] Connect the cable modem directly to the laptop I'm using and you> get a green light. [...] Yeah, I got that the first time. Hence the other (still unanswered)questions.

Cable Modem -> Router (provided by Comcast) -> Router (provided by me) -> Gigabit switch. Various computers are connected to the second router and the switch, either via Wifi or Ethernet for the router and Ethernet for the switch. The first router provides WiFi connectivity for the Comcast security system and nothing else. Breaking the chain and connecting any of the routers or switch to the cable modem results in the light going red. Connecting a computer directly to the Ethernet port on the cable modem results in a green light and communications. Removing the CM1000 and replacing it with the old Motorola cable modem results in communications for all devices tried so far. This help?

> [...] Router (provided by Comcast) Not a very detailed description of anything.> [...] Router (provided by me) Not a very detailed description of anything.> [...] Breaking the chain and connecting any of the routers or switch> to the cable modem results in the light going red. With my weak psychic powers, I don't know how any of these routers isconfigured, and exactly what you're connecting to what remains amystery. According to the CM1000 User Manual, the "Ethernet LED" shouldbe green, amber, or off; "red" seems not to be an expected outcome.> Removing the CM1000 and replacing it with the old Motorola cable modem> results in communications for all devices tried so far. Would it really hurt too much to provide an actual model number forany of these devices?> Any "a single computer", or one specific "a single computer"?> > https://community.netgear.com/t5/x/x/m-p/1574972 Still wondering.> This help? Not really. Too many questions remain unanswered.

CM1000 is not talking to routers over Ethernet

12 Replies

antinode
Guru
May 28, 2018
> [...] After a bunch of fooling around with Comcast [...]

   Not much meat on that bone.

> [...] It is not, however, talking to my network. [...]

   And how would it do that? Through some (unspecified, secret(?))
router or other?

> [...] The Ethernet light is red unless only a single computer is
> connected. [...]

   Any "a single computer", or one specific "a single computer"?

      https://community.netgear.com/t5/x/x/m-p/1574972
- Ghery
  Aspirant
  May 28, 2018
  Snarky replies aren't very helpful...
  
  "talking to my network" means just what you suppose it means - through the Ethernet connection. Connect it to either router or the switch and you get a red light. Connect the cable modem directly to the laptop I'm using and you get a green light. Red light = no joy in communicating with anything over Ethernet.
  - antinode
    Guru
    May 28, 2018
    > Snarky replies aren't very helpful...
    
       Not answering specific questions is what's really unhelpful in these
    situations. Along with information-free problem descriptions.
    
    > [...] Connect it to either router or the switch and you get a red
    > light.
    
       Still wondering what that mysterious "router" might be,
    
       And what is your "the switch"? Connecting a modem directly to a
    network switch would very likely cause trouble with multiple client
    devices. Why involve it, whatever it is?
    
    > [...] Connect the cable modem directly to the laptop I'm using and you
    > get a green light. [...]
    
       Yeah, I got that the first time. Hence the other (still unanswered)
    questions.

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CM1000 is not talking to routers over Ethernet