CenturyLink / Quantum Fiber Router Login
CenturyLink has been rebranding its fiber service as Quantum Fiber since 2021, but whether your bill says CenturyLink or Quantum Fiber, the equipment and login process are largely the same. The admin address for most CenturyLink-provided gateways is 192.168.0.1, and the password is unique to your device — printed on the label.
The most common source of confusion with CenturyLink is the equipment variety. Depending on your service type (DSL or fiber), your market, and when you signed up, you could have one of several different gateway models — each with a different admin interface. Find your model below.
Gateway Models by Service Type
Greenwave C4000 Series — Current Fiber (Quantum Fiber)
The C4000 is the standard gateway for new Quantum Fiber and CenturyLink fiber installations. It is an all-in-one unit handling both the fiber connection and WiFi — no separate ONT in most deployments.
| Admin IP | 192.168.0.1 |
|---|---|
| Username | admin |
| Password | Unique — printed on the bottom label |
| WiFi Standard | WiFi 6 (AX) on C4000XG / WiFi 5 on C4000BG |
The C4000 has a clean, modern admin interface with a dashboard showing internet status, connected devices, and WiFi stats. Key paths: WiFi settings are under WiFi → WiFi Settings, and advanced options like port forwarding are under Advanced Setup. The interface is among the more user-friendly of the ISP-provided gateways.
Zyxel C3000Z — Older Fiber / VDSL Bonded
An older combo gateway deployed for both early fiber and CenturyLink's VDSL (bonded DSL) service, which offered speeds up to 100 Mbps over copper lines before fiber was available.
| Admin IP | 192.168.0.1 |
|---|---|
| Username | admin |
| Password | On device label |
| WiFi Standard | WiFi 5 (AC) |
The Zyxel interface feels dated but is functional. WiFi settings are under Wireless Setup. If you want to check your DSL line sync rate (the actual maximum speed your physical line supports), look under Modem Status → DSL Statistics. This is useful for diagnosing whether slow speeds are a line issue or a network issue.
Actiontec C1900A / C1000A — DSL
The standard gateway for CenturyLink DSL customers, still common in areas where fiber has not been rolled out. Handles both the DSL modem and WiFi router functions.
| Admin IP | 192.168.0.1 |
|---|---|
| Username | admin |
| Password | On device label · Very old units: try admin |
| WiFi Standard | WiFi 4 (N) on C1000A / WiFi 5 (AC) on C1900A |
The Actiontec interface is utilitarian. For WiFi password changes, go to Wireless Setup → Basic Security Settings. The DSL line stats under Broadband show your current sync rate, which reveals whether your DSL line is the bottleneck.
Older / Legacy DSL Modems
Some long-term CenturyLink DSL customers still have older standalone modems (2Wire, Westell, or early Actiontec models) paired with a separate personal router. These modems use 192.168.0.1 or sometimes 192.168.1.254 as their admin address, and many use admin / admin as default credentials since they predate the era of unique per-device passwords.
CenturyLink vs. Quantum Fiber — What Changed
For existing customers, not much changed when Quantum Fiber rolled out in your market. You may have received a new C4000 gateway as part of a proactive upgrade, but the login process and admin panel work the same way. The key practical differences:
| CenturyLink DSL | CenturyLink Fiber | Quantum Fiber | |
|---|---|---|---|
| Typical gateway | Actiontec C1900A | Zyxel C3000Z | Greenwave C4000 |
| Admin IP | 192.168.0.1 | 192.168.0.1 | 192.168.0.1 |
| WAN type | PPPoE (DSL) | PPPoE | PPPoE or DHCP (varies by market) |
| Quantum Fiber app support | No | Limited | Yes |
| Max speeds | Up to 100 Mbps | Up to 940 Mbps | Up to 8 Gbps (multi-gig markets) |
Changing Your WiFi Password
The path varies slightly by gateway model, but the general steps are consistent:
On C4000 (Quantum Fiber): Log into 192.168.0.1 → WiFi → WiFi Settings. You will see separate sections for 2.4 GHz and 5 GHz. Change the WiFi Password field under each, set security to WPA2 or WPA2/WPA3, and click Save. All devices will disconnect and need the new password to reconnect.
On C3000Z: Log in → Wireless Setup → Basic Security Settings. Change the Pre-Shared Key field (that is the WiFi password despite the confusing name). Apply and reconnect.
On Actiontec C1900A: Log in → Wireless Setup → Basic Security Settings. Same Pre-Shared Key field. Change both 2.4 GHz and 5 GHz if you want to keep them synchronized.
Use a password that is at least 12 characters. Avoid obvious choices like your address or the phrase "centurylink" — see our WiFi password guide for recommendations.
Using Your Own Router — PPPoE Setup
CenturyLink fiber customers can bypass the CenturyLink gateway entirely and use their own router. CenturyLink fiber uses PPPoE authentication in most markets, which means your router needs your CenturyLink PPPoE credentials to establish the internet connection.
Your PPPoE credentials are different from your CenturyLink.com account login. The PPPoE username is typically your CenturyLink email address (the one ending in @centurylink.net or @qwest.net). If you do not have these credentials or cannot find them, call CenturyLink support at 1-877-348-9005 and ask for your PPPoE username and password.
Setup steps:
- Connect your router's WAN port to the ONT's Ethernet output (or to the CenturyLink gateway's LAN port if keeping it inline)
- Log into your router's admin panel
- Go to Internet / WAN Settings
- Select PPPoE as the connection type
- Enter your CenturyLink PPPoE username and password
- Save — your router will authenticate and pull a public IP from CenturyLink's network
Checking DSL Line Speed (DSL Customers)
DSL speed is physically limited by the distance between your home and CenturyLink's DSLAM (street cabinet). The farther you are, the lower your maximum sync rate. You can check your actual sync rate in the gateway admin panel — this number is the ceiling for your speeds regardless of what plan you are paying for.
On the C3000Z: Modem Status → DSL Statistics → Downstream Rate. On the Actiontec C1900A: Broadband → Broadband Status. If your sync rate is significantly lower than your plan speed, the issue is your physical line — not the gateway, not CenturyLink's network. Call support to report a line issue or discuss whether fiber is available in your area.
Troubleshooting
192.168.0.1 loads a different device's page: You may have your own router set to 192.168.0.1 as well (common with TP-Link and D-Link routers). To reach the CenturyLink gateway, connect your device directly to the gateway's WiFi or via Ethernet to one of the gateway's LAN ports, bypassing your personal router.
DSL light blinking or off: This is a line sync issue, not a login problem. Check that the phone line is connected to the DSL port (not a phone port). Make sure DSL line filters (small adapters) are installed on every other phone jack in the house that has a device plugged in. If the line was working and stopped, call CenturyLink — it is likely a line fault or network issue on their end.
Admin password not working: Try the label on the gateway. If that does not work, try admin / admin. If both fail, someone changed the password. Factory reset by holding the pinhole reset button on the back for 10–15 seconds while the gateway is on. On DSL gateways this also wipes PPPoE credentials, so have them ready to re-enter.
Internet works but 192.168.0.1 won't load: Try a different browser or clear cache. Run ipconfig (Windows) or ifconfig (Mac/Linux) to check your actual default gateway IP — the CenturyLink unit might have been assigned a different IP if another router is on the same network segment.
Slow speeds on fiber: If you are on a gigabit fiber plan but seeing slower speeds over WiFi, the bottleneck is almost certainly WiFi rather than the fiber connection. Test with an Ethernet cable plugged directly into the C4000 — if you get full gigabit speeds wired but not wireless, the issue is your WiFi device or the distance/obstacles between it and the gateway. See our slow WiFi guide.