USG FLEX H Series [Firewall] - Initial Setup Wizard

This article provides step-by-step instructions for setup/configuring the USG FLEX H Series Firewall. While it won't delve into in-depth configurations, it will guide you through the process of first start and connecting the appliance to the internet and registering it.

We would like to inform you that Zyxel has recently launched the new USG FLEX H devices, which offer high-performance capabilities. Our software department has made significant feature enhancements between the manufacturer version and the version that is shipped out.

In light of these enhancements, it is imperative that you upgrade your firmware version. However, it is MANDATORY that you perform a step-by-step upgrade, rather than directly updating to the latest version.

  • Upgrade brand new H series hardware using the procedure below:
    • Using the initial wizard upgrade firmware from v6.29 to v1.08
    • Using the initial wizard upgrade firmware from v1.08 to v1.10

This article offers a general overview of the series and may not apply uniformly to every model. Prior to purchasing or using the device, please consult the model-specific documentation or reach out to technical support for accurate information.

ATTENTION: USG FLEX H Series - intermediate firmware update during the initial setup

Initial Setup

Before we begin the internet (WAN) setup on the ZLDL router, the following steps need to be completed.

  • Unpack the appliance.
  • Connect the power supply (power cord)
  • Please wait for the device to boot up the device ON (it takes 2-3 minutes to power up)
  • Connect a computer to a LAN port on the device, P5
  • Connect the DSL/Cable modem to the device, P1

Note: For the initial startup of the device, it is necessary that the device is connected to the Internet, as one of the first mandatory steps is to configure the WAN (Internet connection). It is also important to note that after configuring access to the Internet, the mandatory step is to register your device and for this, you will need a My Zyxel Portal account.

Accessing the WebUI

To access the USG FLEX H web configuration page please open a web browser on your computer (Internet Explorer, Mozilla Firefox, Google Chrome, etc.).  On the address bar please type to access the WebUI. The Login screen appears.

Note: Default user name "admin" and password  "1234"

Note: The value in this field is invalid. It can consist of 4-63 characters. The valid characters are [0-9][a-z][A-Z]['(){}<>^`+/:!*#@&=$\.~%,|;-"]. Space is also not allowed. 

Note:  If the default password has been changed, use the new password to login.  If this is the first time setting up the device and it is not accepting the "1234" password, please press the RESET button on the device (located on the front panel) and hold it down for 10-15 seconds

WAN Setup Wizard

  • Connect to Internet step - "The initial setup wizard will appear the first time you log in to the USG FLEX H WebUI. Simply follow the prompts to configure the WAN port connection.  In the first step you can select the interface type, DHCP, Static, PPPoE, and specify the WAN port, it can be Port P1 or P2. 

Click 'Next' to proceed to the next step

  • System Time step - the date, time, and time zone settings will be set automatically. You can change it later in the device menu.

Click 'Next' to proceed to the next step.

  • Device Registration step - you must register your Zyxel Device to activate security services and upgrade firmware. Make sure your Zyxel Device can access the Internet. Click Register to go to Nebula Control Center (NCC) to register your Zyxel Device. NCC is an Internet portal that allows you to manage and monitor groups of Zyxel Devices in organizations.

To register your USG FLEX H firewall with Nebula, please select an Organization and a Site under your authority, or create new ones. You organize Zyxel devices in Nebula into Organizations, for example, "YourCompany" or "YourClient", and Sites, for example, "London Branch" or "Factory".

Please review your device & license information and follow the prompts in the registration menu to complete the registration of the new device. After all, steps have been completed, you will return to the "Device Registration" step and the registration status will change to "Registered".

If you don't have a MyZyxel portal account or wish to register your device on the MyZyxel portal directly, please follow the instructions provided in the following link. This article covers all aspects of device registration:

Firewall [MyZyxelPortal] - registration/transfer/re-register/unregister process

Click 'Next' to proceed to the next step.

  • License Summary step - the next step automatically activates all services to which you have a subscription.

Click 'Next' to proceed to the next step.

Finish step - Click Finish to exit the wizard.

Next, use the web configurator to configure settings such as security policies and services. Log into the Nebula Control Center (NCC) to monitor and manage your Zyxel Device.


If you encounter issues during the 'Connect to the Internet' step, please review your settings:

  • Verify the interface type is correctly configured. Ensure that you are obtaining an IP address automatically, or, if necessary, specify it manually.
  • Confirm the port to which the Internet cable is connected—whether it's P1 or P2. Ensure that you have selected the appropriate port."


Troubleshooting Internet Connectivity Issues

If you're experiencing internet connectivity problems, follow these steps to diagnose and resolve the issue:

  1. Verify ISP Parameters and IP Address Assignment:
    • Check your ISP settings and ensure they match the information provided by your service provider.
    • Confirm that the IP address assignment settings are correctly configured.
  2. Check WAN Connection:
    • Ensure that P1 (WAN Port) on the USG FLEX H is properly connected to your DSL or Cable modem.
  3. Reset Cable Modem Cache (for cable modem users only):
    • Note: If your cable modem also provides telephone service, do not proceed with this step; contact your ISP for assistance.
    • You have three options to reset the cable modem: 
      • Press and hold down the RESET button for 15 seconds to clear the cache.
      • If the modem doesn't have a RESET button, power it down for 5 minutes. Remove the power cable and battery backup (if applicable).
      • Contact your cable internet provider to request a modem cache reset from their end.
  4. Verify DSL Modem Mode (for DSL modem users):
    • Many DSL modems function as modem/router combinations. It's recommended to contact your internet service provider and request that they set the modem to bridge mode for optimal compatibility with your Firewall.
  5. Reboot the Firewall:
    • Restart your USG FLEX H device to refresh its settings
  6. Contact Zyxel Technical Support:

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