GreenWave C4000LZ WiFi 6 Modem Router | CenturyLink, Brightspeed

The renewed GreenWave C4000LZ is a WiFi 6 modem router built for CenturyLink and Brightspeed internet. It is the highest-throughput CenturyLink gateway we carry, with download speeds up to 2.5 Gbps, five Gigabit Ethernet ports, and a dedicated WAN port that lets it run as a standalone router on fiber. One device replaces your rented gateway and your router, ending the monthly equipment fee. Every unit is professionally tested and backed by our 90-day full coverage warranty.

Key Takeaways

• WiFi 6 (802.11ax) gateway with dual-band coverage, Smart Connect band steering, and backward compatibility with older WiFi devices (a/b/g/n/ac).
• Speeds up to 2.5 Gbps download and 1 Gbps upload, with five Gigabit Ethernet ports (1 WAN + 4 LAN) for wired stability.
• Works with CenturyLink DSL and fiber and is used on Brightspeed service in former CenturyLink territories (confirm with your provider before ordering).
• Replaces rented gateway equipment, typically saving $180 per year, with a 90-day full coverage warranty and USA-based support.

Is the GreenWave C4000LZ Compatible with My Internet Provider?

The C4000LZ is built for CenturyLink DSL and fiber-optic internet. It is also used on Brightspeed service in the former CenturyLink territories Brightspeed now operates. Its dedicated Gigabit WAN port lets it act as a standalone router on fiber deployments, while the DSL side covers standard copper plans. Confirm the C4000LZ is approved for your specific plan and address before ordering, since deployment types vary. For setup help, see our CenturyLink activation guide or Brightspeed activation guide.

The C4000LZ does not work with cable internet (Xfinity, Spectrum, Cox), Verizon Fios, AT&T service, satellite, or 5G home internet.

Which CenturyLink Gateway Should You Buy?

We carry four CenturyLink-compatible gateways, and each fits a different situation. The C4000LZ is the performance pick, with WiFi 6 and the highest speed ceiling of the group, making it the best match for fiber and top-tier plans. The GreenWave C4000LG is its WiFi 6 sibling for standard single-line DSL plans up to 1 Gbps. The Actiontec C3000A covers bonded (two-line) VDSL2 and G.fast plans. The Technicolor C2100T is the budget pick and the only one with VoIP phone ports for CenturyLink home phone service. Not sure which line type you have? Your provider can tell you in one quick call.

WiFi 6 Performance

Built on the WiFi 6 (802.11ax) standard, the C4000LZ handles many high-bandwidth devices at once, keeping 4K streaming, gaming, and video calls smooth in busy households. Dual-band 2.4 GHz and 5 GHz radios provide strong signals and wide coverage, and backward compatibility means older WiFi devices connect without issue. Smart Connect automatically assigns each device to the best band under a single unified network name, while Dynamic QoS prioritizes streaming, gaming, and call traffic to reduce lag and buffering.

Wired Connectivity

Five Gigabit Ethernet ports (1 WAN + 4 LAN) give you flexibility most DSL gateways lack. Wire up gaming consoles, desktops, and smart TVs for maximum stability, and use the dedicated WAN port to run the C4000LZ as a standalone router on fiber service.

Security and Setup

Modern encryption and security protocols protect your data, and the guided setup wizard gets you online in minutes. Once running, the built-in management interface lets you customize settings, monitor connected devices, and adjust your network in a few clicks.

GreenWave C4000LZ Specs at a Glance

Save on Modem Rental Fees

CenturyLink and Brightspeed charge around $15 per month to lease a gateway, which is $180 a year for equipment you could own. At its current price, this renewed C4000LZ pays for itself in about six months, and everything after that is savings. If your rented gateway is aging or dropping connections, our guide on how long modems last covers the signs it is time to replace it.

What's in the Box

• GreenWave C4000LZ modem router (Renewed)
• DSL cord
• Ethernet cable
• Power cord

Why Buy the GreenWave C4000LZ from ModemGuides

• 90-day full coverage warranty on every modem we sell, including this renewed C4000LZ.
• USA-based customer service and tech support staffed by people who actually know networking gear.
• Fast shipping from US warehouses, so most orders arrive in 1 to 3 business days.
• Curated, ISP-compatible inventory: we only stock modems and routers that are approved on real plans, with clear compatibility notes on every listing.
• Setup and troubleshooting guides available across ModemGuides.com to help you get online without the runaround.
• Small US business that puts customer experience first, with real humans answering your questions.

GreenWave C4000LZ Frequently Asked Questions

Is the GreenWave C4000LZ compatible with CenturyLink?

Yes. The C4000LZ is built for CenturyLink and works with both DSL and fiber-optic deployments, using its DSL port for copper plans and its dedicated WAN port for fiber.

Does the GreenWave C4000LZ work with Brightspeed?

The C4000LZ is used on Brightspeed service in the former CenturyLink territories Brightspeed now operates. If you are a Brightspeed customer, confirm the C4000LZ is approved for your plan and address before ordering.

What is the difference between the C4000LG and C4000LZ?

Both are WiFi 6 gateways in GreenWave's C4000 family. Based on our listings, the C4000LZ supports higher speeds (up to 2.5 Gbps download versus 1 Gbps) and adds a fifth Gigabit port as a dedicated WAN, making it the stronger pick for fiber and top-tier plans. The C4000LG covers standard single-line DSL plans up to 1 Gbps at the same price point. Both work on CenturyLink and Brightspeed service.

Can the C4000LZ be used with CenturyLink fiber?

Yes. The dedicated Gigabit WAN port lets the C4000LZ run as a standalone router on fiber deployments. Fiber setups vary by address, so confirm with your provider before ordering.

Is the C4000LZ a modem and a router?

Yes. The C4000LZ is an all-in-one gateway with a built-in WiFi 6 router, so you do not need any separate hardware to get online.

What is Smart Connect?

Smart Connect broadcasts one network name and automatically assigns each device to the 2.4 GHz or 5 GHz band with the best signal, so you never have to choose bands manually or juggle multiple network names.

Will older WiFi devices work with the C4000LZ?

Yes. The C4000LZ is backward compatible with 802.11 a/b/g/n/ac, so older laptops, phones, and smart home devices connect right alongside newer WiFi 6 hardware.

Is this C4000LZ new or refurbished?

This C4000LZ is a Renewed unit that has been professionally inspected and tested, backed by our 90-day full coverage warranty.

What happens if the modem stops working?

If anything goes wrong within the first 90 days, contact our USA-based support team and we will troubleshoot, replace, or refund. We stand behind every modem we ship.