Speedi1's profile

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Saturday, April 17th, 2021 2:22 PM

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Nighthawk CM1200 Incompatible with 1.2Gb Service?

Looking at my device compatibility with the new 1.2Gb service I have, it claims the cm1200 is incompatible. I know this modem can handle the speeds so what's the story?

Gold Problem Solver

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26.3K Messages

4 years ago

The page at https://www.xfinity.com/support/devices/ lists 5 retail devices approved for 1.2 Gbps. They all appear to have 2.5 Gbps Ethernet ports, the CM1200 does not seem to have one.

It might be possible to get a bit more than 1 Gbps through the modem using a router compatible with its link aggregation, but if Comcast doesn't deliver 1.2 Gbps to the CM1200, I don't think it can provide the full benefit of the 1.0 to 1.2 speed upgrade.

Official Employee

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1.8K Messages

4 years ago

Good morning @Speedi1 and thank you so much for reaching out to our Digital Care Team on our forums page. To ensure your modem is compatible please use the My Device website here https://comca.st/3tx9KV4 to easily check if your device is approved for Xfinity Internet service.  My Device shows a database of all approved cable modems. You can also use this site to make sure your modem or router supports your selected Internet speed tier.

 

What speeds are you currently experiencing? If you are having connection issues, rest assured you've reached the right team to help. What troubleshooting steps have you attempted thus far? 

Regular Visitor

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16 Messages

4 years ago

Heres the thing. the cm1200 and my modem the motorola mb8600 will provide higher than 1 gig thru wan aggregation. Because its labled as a gigabit router,comcast says its incompatible. This is false. By bonding two ethernet ports on the modem..and connecting the two cables to a compatible router that also supports wan bonding...you will see higher than 1 gig speeds. Just remember that you will need a lan port that is labled for at least 2.5g on the router and your network card in your computer if your hardwired is also rated for at least 2.5g Proof it works just fine.

This comment was created from this reply

Problem Solver

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948 Messages

So even if your modem doesn’t support link aggregation, with a router like the asus  rt-ax86u, if you have 2 gigabit Ethernet connections to supply it and use dual wan setup, it will achieve roughly 1400 Mbps, this is just for reference, also the some select asus routers can use the Merlin firmware, which is enhanced asus firmware, the great thing about the Merlin firmware, is you can download the source and compile your own custom firmware

Visitor

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1 Message

4 years ago

So I have purchased the Netgear CM1200 just recently, upgrading from the CM700 due to the fact that I cannot utilize the full 1.2 GB speed. My router is Nighthawk X6 AC3200. Xfinity is saying that I still cannot utilize my 1.2 GB speed plan. Do you know what steps I can take to use my full coverage? Or am I just [EDITED] again and need to buy another piece of hardware?

EDITED: Language

(edited)

Visitor

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1 Message

@user_630ce6

Your router (X6 AC3200) is not capable of multi-gig speeds.  Your router also does not have a 2.5G Multi-Gig Ethernet Port.  You would need, for example, a router like the RAX200 or RAX120 which supports multi-gig internet which in this case would be utilizing LAG to achieve the 1.2+ Gbps you are paying for.  Honestly @Chinga explained this very well a few replies above so I will just copy-paste his explanation again for you:

"By bonding two ethernet ports on the modem..and connecting the two cables to a compatible router that also supports wan bonding...you will see higher than 1 gig speeds. Just remember that you will need a lan port that is labled for at least 2.5g on the router and your network card in your computer if your hardwired is also rated for at least 2.5g Proof it works just fine."

Expert

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110K Messages

4 years ago

The original poster has not returned. 5 month old dead thread now being closed.

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