NETGEAR CM1200 Review: Great for 1Gbps, Limited Beyond
The NETGEAR Nighthawk Cable Modem CM1200 emerges as a product with strong performance credentials but some notable limitations that have frustrated certain buyers. While officially marketed as a DOCSIS 3.1, multi‑gig capable modem supporting up to 2 Gbps plans, cross‑platform feedback suggests its real‑world performance is consistently capped by gigabit Ethernet ports, making it best suited for cable plans up to 940 Mbps unless link aggregation is deployed—an approach several users found unstable. Based on aggregated feedback, the CM1200 scores 7.6/10.
Quick Verdict: Conditional — Excellent for high‑speed cable plans up to 1 Gbps, but users seeking beyond‑gigabit speeds should proceed with caution due to port limitations and ISP compatibility constraints.
| Pros | Cons |
|---|---|
| Stable DOCSIS 3.1 performance in most setups | Gigabit port cap limits >1 Gbps speeds |
| Works with Xfinity, Spectrum, Cox | Link aggregation implementation unreliable |
| Four gigabit Ethernet ports | Confusion over multi‑IP address support |
| Easy activation with major ISPs | Poor documentation and setup guidance |
| Saves up to $168/year vs ISP rental fees | Some refurbished units shipped faulty/misconfigured |
| Solid build quality | No router/Wi‑Fi functionality |
Claims vs Reality
NETGEAR advertises “true multi‑gig internet speeds” with link aggregation, promising support for cable plans up to 2 Gbps. While this is technically possible, Reddit user u/jay_w reported that “the CM1200 is limited with 1 Gb ports… I tried the lag connection… worked for 24 hours… then dropped below my baseline.” This instability in link aggregation was echoed on Twitter, where Bill L. said, “great spec, with almost useless LACP implementation.”
Another marketing claim is its “multi‑IP address support” for up to four home networks. In practice, multiple buyers found this feature dependent on ISP provisioning. A verified Spectrum customer on NETGEAR Communities explained, “only the initial [port] gets an IP… the others sit there looking stupid,” later confirming that their ISP had reduced them to a single IP despite paying for multiples.
Finally, NETGEAR highlights “compatibility with all major US cable internet providers.” While generally true, there are ISP‑specific speed caps: Amazon’s listing notes certification at 800 Mbps for Xfinity, 1 Gbps for Spectrum and Cox. Reddit discussions revealed Spectrum’s D3.1 2.5G EMTA modem outperforms the CM1200 for >1 Gbps plans due to its 2.5 Gbps port.
Cross‑Platform Consensus
Universally Praised
Users consistently praised the CM1200’s stability on sub‑gigabit plans. Reddit user plemans shared, “Spectrum has been running strong on this thing ever since I got it… handles 3 Xboxes, 4 TVs, 4 phones, and a tablet all having internet access at once without breaking a sweat.” Amazon buyers noted easy activation: Joseph E. described plugging in, waiting for connection, and being “redirected to the Xfinity activation page… online in minutes.”
The device’s DOCSIS 3.1 support earned approval from heavy internet users. Buyers on Trustpilot emphasized its “future‑proofing” for upcoming higher‑speed tiers, with one review noting it “fully supports IPv6” for modern networking needs. Those upgrading from rented ISP modems appreciated the savings, with multiple reports of annual equipment fee reductions of $150‑$170.
Common Complaints
A recurring frustration involves the gigabit port limitation. Twitter user James W. achieved “around 900 Mb/s” on a 1 Gb plan, but could not surpass that without unstable link aggregation. This matters most to users with >1 Gbps service and compatible routers, as the CM1200 cannot match newer modems with 2.5 Gbps ports.
Documentation gaps also drew criticism. A Spectrum customer on NETGEAR Communities was “surprised with the lack of paperwork… and the lack of info in the ‘support’ section,” leading to confusion over Ethernet port functionality. Several refurbished unit buyers reported DOA devices or misconfiguration, such as Chad C.’s “better part of a Sunday on the phone with Comcast… modem determined to be faulty.”
Divisive Features
The four Ethernet ports are a case in point. Some users assumed they could connect multiple devices directly for separate public IPs, but most ISPs only provision a single IP per account unless special arrangements are made. For gamers or small offices with IP blocks, the CM1200 could be ideal—if the ISP cooperates. Others found the ports more useful for connecting to a router or for link aggregation, though as noted, LACP support is patchy.
Trust & Reliability
Trustpilot and Reddit feedback suggest the CM1200 is generally durable once properly configured. Owners reported years of uninterrupted service, apart from occasional ISP outages. However, refurbished units present risk: multiple Twitter reviewers received scuffed or faulty modems, sometimes in unmarked boxes. This raises concerns about third‑party refurbishing quality and reinforces the need to buy from authorized sellers.
Long‑term users like Reddit’s plemans described it as “ol’ faithful” since day one, capable of handling multiple simultaneous streams and gaming sessions. Conversely, some noted it “runs a bit warm” and requires occasional reboots, especially when using advanced features like link aggregation.
Alternatives
The most direct comparison in user data is Spectrum’s D3.1 2.5G EMTA modem. Reddit consensus favors the Spectrum modem for >1 Gbps service and upcoming mid/high‑split upgrades, as “Netgear only has gigabit ports which caps you at 940 Mbps.” For budget buyers, the Netgear CM600 offers stable DOCSIS 3.0 performance at lower cost, though without future‑proofing.
Price & Value
Officially priced at $249.99, the CM1200 often sells for less—eBay listings show certified refurbished units at $159.99, with used options as low as $46.98. Resale values remain strong due to DOCSIS 3.1 capability, but community members advise caution with non‑authorized refurbishers. Buyers highlighted the cost savings versus ISP rentals, especially for those planning to keep the modem for several years.
FAQ
Q: Can I use all four Ethernet ports for separate devices without a router?
A: Only if your ISP provisions multiple IP addresses. Most ISPs provide a single IP, making additional ports useful mainly for router connections or link aggregation.
Q: Does the CM1200 include Wi‑Fi?
A: No, it is a modem only. You will need a separate wireless router to connect Wi‑Fi devices.
Q: Will it work with my >1 Gbps cable plan?
A: It can, but speeds above ~940 Mbps require link aggregation, which some users found unstable. For over‑gigabit plans, consider a modem with a 2.5 Gbps port.
Q: Is it compatible with Verizon or AT&T fiber?
A: No, it only works with cable internet providers like Xfinity, Spectrum, and Cox, and is not compatible with DSL or fiber services.
Q: Can I avoid ISP rental fees with this?
A: Yes, many users reported saving $150‑$170 per year by purchasing this modem instead of renting from their ISP.
Final Verdict: Buy if you have a high‑speed cable plan up to 1 Gbps and want a stable, ISP‑compatible DOCSIS 3.1 modem with multiple Ethernet ports. Avoid if you require >1 Gbps without relying on link aggregation, or if your ISP does not support multiple IP addresses. Pro tip from community: purchase from an authorized seller to avoid faulty refurb units and ensure warranty coverage.
