1.37 uOS - errors when you set DHCP table from Nebula

GiuseppeR

Hello everyone,

I was testing new firmware to deploy in production.

As you set DHCP table on Nebula:

While if you log in to your firewall and set it from there everything is smooth:

Why I cannot set the DHCP reservation from Nebula?

Zyxel_Barry

Hi @GiuseppeR,

Thank you for reaching out to the Zyxel Community regarding the DHCP reservation issue on your USG FLEX H Series device managed by Nebula.

The error message "IP address is incorrect format" when setting the DHCP table from Nebula suggests a potential discrepancy or formatting requirement in the Nebula interface. While the local GUI allows for seamless configuration, Nebula may have specific input validation.

Here's a guide to help you troubleshoot and resolve this:

• Review Nebula DHCP Configuration for USG FLEX H Series:

  • Navigate to Site-wide > Configure > Firewall > Port & Interface in your Nebula console. This is where you configure static DHCP clients directly from the interface page for USG FLEX H Series.
  • Carefully examine the format of the IP addresses you are trying to reserve. Ensure there are no leading/trailing spaces or invalid characters.
  • Verify that the IP addresses you are trying to reserve fall within the defined DHCP pool for that interface.

• Verify Firmware and Nebula Compatibility:

  • Ensure your USG FLEX H Series firmware (uOS) and Nebula Control Center are running compatible and up-to-date versions. Nebula 18.30 introduced cloud configuration management and synchronization for H Series firewalls, and updates often include specific behaviors for configuration synchronization.
  • Check for any known issues or release notes related to DHCP reservations for your specific firmware version on USG FLEX H Series in conjunction with Nebula.

• Utilize Local GUI for Verification (if still an issue):

  • Although the goal is to configure via Nebula, temporarily setting a DHCP reservation via the local GUI (Network Status > DHCP Table) and then observing how Nebula reflects or attempts to synchronize it can provide insight into potential conflicts or formatting differences.

To further investigate, please provide the following information:

• Nebula Organization and Site Name: This will allow our support team to directly view your cloud environment configuration and expedite troubleshooting.
• Firmware Version: The exact firmware version (e.g., 1.37 uOS) running on your USG FLEX H Series.
• Screenshots: If the error message in Nebula provides more details or if there are other relevant error messages in the Nebula event logs, please include screenshots.
• Network Topology: A brief description or diagram of your network setup.

Zyxel_Melen

Hi @GiuseppeR

This is a known issue on Nebula. It will be fixed this Tuesday.

Zyxel_Melen

Update:

The issue is fixed on 2026/1/27.

GiuseppeR

Hi @Zyxel_Melen

thanks for the update