You may not need that C4000XG Firewall Settings

    C4000XG Firewall Settings

    You may not need that C4000XG Firewall Settings

    C4000XG Firewall Settings

    After realizing that CL gigabit fiber was $15 cheaper than their 200mbps down/12mbps, I received it from Comcast in Portland. Since broadband was a thing, I have had cable internet. I am very particular about being allowed to bring my equipment.


    I am a software engineer and have a very high tolerance for poorly implemented firmware. This is what plagues the routing devices provided by telecom companies to their customers. I tried DD-WRT for a time when the WRT54g device was available (as well as a few other alt firmware – remember Tomato?) ).


    You can therefore imagine my surprise when the tech arrived with the monstrous-looking air purifier and my confusion when I heard him refer to it as the “modem” AND “router.”


    It’s not a modem C4000XG edition

    C4000XG Firewall Settings

    This shows that the additional device provided by the service provider does not do anything special. It does not convert signals in the same way as a telephone or cable modem, and it does not directly relate to the fiber media (that is, the domain of the fiber terminal).


    It doesn’t do anything that isn’t possible with many consumer-grade routers or internet gateways. The C4000XG does not function as a modem and may not be necessary.


    If you have read this far and are still interested in networking hardware that can do all you need, there is probably a piece of it lying around. You will need these items if you want to get rid of your telecom-provided router.

    • Your PPPoE username
    • Your PPPoE password
    • An internet gateway device that:
      • Supports PPPoE authentication and VLAN tagging (DDWRT does this).
      • Has enough processing power for gigabit speeds, including security processing
        • It’s a smart idea to use a dedicated device for your gateway and have all other features (such as WiFi) handled by another device.


    Locate your PPPoE credentials

    According to what I read, you can call CenturyLink support or use the chat to request your PPPoE information. As a CenturyLink customer, this Saturday was my fourth or fifth day.


    (Well, Friday if you include the installation tech not showing up, not calling to inform me, then turning up at 9:30 on Saturday morning). I don’t want any additional communication from CenturyLink. It’s easy to find the dev tools for your browser if you are familiar with them, at least on the C4000XG firewall setting.

    1. If your C4000XG has not been set up yet, please follow the guide to connect it to the internet.
    2. Log in to the admin GUI.
    3. Check that your browser is recording network requests. (This is often enabled by default, I believe)
    4. In the admin GUI, click “Quick Setup.”
    5. In the dev tools “network” tab, look for a request to It was there for me. You may have to filter for “XHR”requests. Click on the link and click on it..
    6. Click on “response,” hit CTRL+F or CMD+F on Mac, and type Username. Your username and your password should appear below. My username is eight alphanumeric characters.

    Configuring your hardware

    Additional disclaimer: CenturyLink will likely limit your options for tech support once you have completed this part. I don’t think they’ll support anything, not on their Compatibility list. Therefore, any problem you encounter that’s not directly related to their fiber terminals or their wiring outside of your house will be your responsibility to resolve.


    You can now disconnect the C4000XG, throw it out with the rest, or return it to CenturyLink. Next, connect the Ethernet cable from the fiber terminal to the WAN port of your choice.


    Specifications vary depending on the firmware and device. I assume that you know at least some of what you are doing and are familiarized with the configuration of your device.

    1. If your device can act as a router or gateway, ensure it is set up in “gateway” mode. (DD-WRT users: Refer to the “Advanced Routing,” “Operating Mode” tab).
    2. You can configure the WAN port on your device – there may be a “port type” C4000XG Firewall Settings that allows you to choose between DHCP or PPPoE. DD-WRT also offers PPTP and L2TP. Of course, you want PPPoE.
    3. Enter your username and password that you received from the C4000XG administrator
    4. Set the VLAN ID (also known as the VLAN number or tag) to 201
      1. You will need to click on the “Networking” tab for DD-WRT users. Add a VLAN tag using 201 as the number. Select the right interface. Fair warning: I have not done this on a DD/WRT device.
      2. I have an UniFi USG3 and had to use the admin UI of the security gateway (via the gateway’s LAN IP address) to set the VLAN Tag. This C4000XG Firewall Settings is not available through the controller.
    5. Set your settings and relax!
    Read More: What does nucypher use to protect your data


    Fiber terminals are just dumb terminals. They provide a connection to the internet but do not offer any security features. This is the job of the gateway/router device that you just disconnected. Ensure you have a firewall on your gateway device to protect you from hackers and script kids.