[ATP/FLEX/FLEX H] What is the maximum number of DHCP Pool supported on Nebula firewall?

Hi @Dylan96

Nebula Native Mode is designed to simplify the deployment of Nebula firewalls (USG FLEX/ATP series) on the cloud. However, for the USG FLEX H series firewall, it will be introduced in a hybrid mode, not Nebula Native Mode. This hybrid mode allows configuration through both the Nebula Control Center (NCC) and locally, which is different from the previous firewall model.

With the latest uOS 1.30 release, the USG FLEX H series already supports some Nebula features, including:

• Nebula Topology
• Nebula Security Profile Sync
• Nebula Site-wide Device Status
• Nebula Site-wide Event Log

You can find more details in the release note:

USG FLEX H Series - V1.30 Patch 0 Firmware Release

To ensure seamless integration with Nebula, we're continually working to enable more features, so additional development is necessary. The full functionality is expected by 2025, stay tuned to our https://community.zyxel.com/en/categories/nebula-news-and-new-release .

Hi @TranAnhDung

There is no restriction on the IP pool size; as long as it fits within Class A, B, or C, it can be configured. However, the actual number of users supported will depend on the device's capacity. You can refer to the recommended number of users by filtering the Number of Users at:

https://www.zyxel.com/global/en/products/next-gen-firewall

Hi @HienDang

Here’s a breakdown of why recommended user limits are set as they are across different models, even when some models (like the FLEX100H) have higher hardware specifications.

1. Criteria for Recommended User Limits

The recommended user limits are based primarily on each device’s capacity to handle concurrent sessions and logins, especially with security features enabled. Key factors include:

• Concurrent Sessions: Each device has a maximum number of active sessions it can handle. Higher session numbers can strain resources, even with ample bandwidth, which is why user recommendations are set to help ensure stable performance.
• Concurrent Logins: User limits also consider the number of users actively logged in simultaneously. With more users accessing secure or data-intensive applications, the device’s resources are further taxed.
• Security and Processing Requirements: Devices using security-intensive features—such as VPNs or advanced threat detection—may have tighter user caps to maintain high-quality performance for these tasks.
• VPN Tunnels: The capacity for VPN tunnels is another factor in determining recommended user limits.

These limits serve as general guidelines for product sizing, but you’re welcome to adjust the user numbers based on your specific applications, scenarios, or market needs.

2. Performance with New uOS Updates

We understand there may be perceived differences in performance with new uOS versions. Here’s some context that may be helpful:

• Enhanced Performance with uOS: The new uOS generally improves Firewall and VPN performance.
• Prioritizing Security and New Features: New uOS versions often come with added security features and optimizations. While these updates improve functionality, they may also increase processing demands, creating a temporary perception of slower performance. Adjusting resource-intensive settings can help fine-tune the device’s operation to best suit your requirements.

I hope this explanation provides clarity on the model specifications and user limitations.