Using your Zyxel C4000LZ modem

Recommended CenturyLink modem

Zyxel C4000LZ modem

Features of the Zyxel C4000LZ

  • Secure WiFi compatible
  • WiFi 6 technology with dual-band 2.4 GHz and 5 GHz 802.11ax
  • Smart Connect single wireless network (SSID): Auto-selects the fastest band for each device
  • Single LED status light 
  • Dynamic QoS: Prioritizes data through the router for smoother streaming
  • Standards-based WiFi WPA3 security

NOTE: This router has the same specifications as the Greenwave C4000LG

Works with these CenturyLink internet services:

  • ADSL/ADSL2+/VDSL – single line up to 100 Mbps

Note: Listed speeds reflect the maximum speed the technology can accomodate. In-home speeds may differ based on router setup, devices and other factors.

Diagram of the C4000LZ modem

Modem troubleshooting tips

Tip: If the download link doesn't work correctly, try another browser, OR right-click the link, select "copy link address", then paste the link into a new browser tab.

Quick setup

Manual network (WAN) setup

If instructed to do so by a technician, you may need to change the WAN settings on your modem manually. Visit the WAN setup page for step-by-step instructions on different WAN configurations, including PPPoE, IPoE and transparent bridging.

Your modem's wireless settings control the WiFi network in your home. This model of router has 2.4 GHz and 5 GHz options for most wireless settings, with exceptions noted below. Click on the options below for details and step-by-step instructions.

Helpful WiFi topics

WiFi extenders: If you have a C4000 modem and would like to boost your signal, we recommend ordering a compatible WiFi extender on our Accessories Marketplace.

The modem status area of the user interface allows you to view several options and check how your modem is running. 

  • Firewall status
  • Device table
  • NAT table
  • Routing table
  • QoS table
  • Resource table

The utilities menu gives you access to several additional tools to manage and test your modem. 

Advanced settings give you even more control over your modem's configuration. Most of these are best for tech-savvy folks who are familiar with modems and networking. 

Setting up new service? Please note that a phone jack is required to set up CenturyLink internet service in your home. If you don't have a jack, chat with us to have one installed.

Introducing Secure WiFi

Secure WiFi provides automatic cybersecurity for your network and all devices connected to it, plus:

  • Manage network services
  • Manage devices
  • Pause devices
  • Create groups


Introducing WiFi 6

Intel WiFi 6 Gig+ is the next generation in-home WiFi technology, designed for the ever-increasing demand of connected homes and gigabit connections. Compared to WiFi 5, it delivers:

  • Up to 3x the connectivity speed 
  • Up to 4x the data capacity 
  • Up to 75% less lag time (latency) for gaming and video applications

WiFi 6 also includes embedded cybersecurity, managed network services and parental controls. This feature is available with the Greenwave C4000 modem/router.

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