CM1100 will not accept more than one device

[aaronmcd1214]

Trying to get my new modem setup and it appears that only 1 LAN port will provide internet access at a time. Called Cox to activate the modem and plugged my PC into it directly to test and everything worked. Then I tried plugging in my Orbi router to get it going but kept getting a 'no internet' connection error. Plugged my laptop into it directly and confirmed it would connect to the network (though I couldn't access the modem through it's IP) but no internet access. Tried resetting w/o the coax plugged in and it appeared to be working ok but the PC in the first port wasn't receiving internet now. Unplugged the laptop and reset, PC now has internet but 2nd port will not work. Is this just a defective unit perhaps?

[plemans · Accepted solution]

No, its just a bad explaination by Cox and Netgear.

the dual port on the cm1100 is designed for port aggregation (which most routers don't have) or for ISP's that allow multiple public IP addresses (most don't). I know comcast and cox don't allow it free. You can pay extra or get a business line that allows it but the standard setup doesn't. 

So for the average user, the 2nd port is useless. 

Try shutting off both the modem and router and disconnecting everything from the modem.

Power the modem back on and give it a few minutes. 

then connect port 1 of modem to the wan port on the orbi. 

The power up the orbi. Give it a few minutes and then try going through setup. 

[plemans · Accepted solution]

No, its just a bad explaination by Cox and Netgear.

the dual port on the cm1100 is designed for port aggregation (which most routers don't have) or for ISP's that allow multiple public IP addresses (most don't). I know comcast and cox don't allow it free. You can pay extra or get a business line that allows it but the standard setup doesn't. 

So for the average user, the 2nd port is useless. 

Try shutting off both the modem and router and disconnecting everything from the modem.

Power the modem back on and give it a few minutes. 

then connect port 1 of modem to the wan port on the orbi. 

The power up the orbi. Give it a few minutes and then try going through setup. 

[aaronmcd1214]

Thanks for clarifying. My previous setup was with an Arris Surfboard combo unit that had 4 ports on the back and every device plugged into it worked. I'm assuming those were different then?

[plemans]

It was problem a modem/router combo device. 

the CM1100 doesn't have an integrated router. Its a modem only device. 

[plemans]

Mean to say probably, not problem.

[aaronmcd1214]

Got it. Thanks for helping me understand!

[FURRYe38]

The CM1100 is just a modem, not built in router. 

You can connect two external routers behind the CM1100 though. It works. 

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@aaronmcd1214 wrote:
Got it. Thanks for helping me understand!

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[aaronmcd1214]

I've got my router plugged into the modem and an unmanaged switched into the router and it looks everything is good to go. Thanks for the quick responses!

[FURRYe38]

Enjoy. 

[Retired_Member]

Page 9 of the User Manual. You should be able to utilize BOTH ethernet ports simultaneously in a non-link aggregation mode.

https://www.netgear.com/images/datasheet/networking/CableModems/CM1100.pdf

Stunned that some "super users" just dismiss this key functionality that exists even in the devices marketing. Each device has its on connection to the web (Not a unique IP but essentially an isolated LAN of it's own).

[plemans]

Love how people leave quick comments to stir things up and then "retire".

No, it doesn't work that way. Can you connect more than 1 device to the cm1100? Sure, if your ISP supports that. 

Sadly, most don't. 

[FURRYe38]

Yep. They seem to assume incorrectly that these modems can do or presume they are a router just because they have more than 1 ethernet port thinking it's a router. They fail to not fully understand what the CM series supports and what ISPs do and do NOT support. 

Thankfully my ISP is supportive of having more than 1 WAN address. I've had both CM1100 and CM1200 online with more than 1 router connected. Just yesterday I had 3 different routers connected to my CM1200. All had different WAN IPs. 

Also would have been nice if the ex-user had posted the link to the user manual and NOT the data sheet which is only 5 pages. 🙄