topic UPPAK Becoming Mandatory on R82.10? Important Findings About KPPAK Support, Boot Loops on 19000 in General Topics

UPPAK Becoming Mandatory on R82.10? Important Findings About KPPAK Support, Boot Loops on 19000

israelfds95 — Fri, 15 May 2026 14:59:12 GMT

We know Check Point already introduced the change making UPPAK the default, while still allowing the option to switch back to KPPAK. We saw very strongly during R81.20 and early R82 versions that several firewalls running UPPAK presented many anomalous issues with no clear solution, and only became stable again after switching back to KPPAK.

However, this week, while trying to configure a 19100 firewall running R82 JH 91 with KPPAK, I faced the error below, and the firewall entered a boot loop freeze, even though sk179432 still describes support for it.

Below Error encountered during boot when changing a 19100 firewall from UPPAK to KPPAK:

I switched back to UPPAK and the firewall is operating normally again, so I got important information that I think is worth sharing.

The sk167052 – “User Space Firewall (USFW) support on Security Gateways” documents that:

KPPAK will no longer work starting from R82.10
Firewalls with more than 40 CPUs, with or without HyperThreading enabled, may or can experience boot crashes

Below is the response from Check Point:

It is important to prepare for this scenario. Those who previously had major issues with UPPAK freezing firewalls, buffer overflows, and environments stuck in a “no solution” situation where the only workaround was switching to KPPAK — whether on older firmware/firewall generations or even newer platforms — should be aware and prepare for this major definitive change that is coming. On high-end platforms like the 19000 and 29000 series, it seems we will fully move forward with UPPAK only.

I also want to raise a complaint

regarding the lack of synchronization and updates across SK documentation. One SK (sk179432) still states that 19000 and 29000 appliances support KPPAK, while another SK (sk167052) already mentions the boot crash issue on firewalls with more than 40 CPUs.

It is extremely important for documentation to be unified and kept updated in order to provide accurate information for all of us in the community who work daily with the solution. When issues happen, we rely on the vendor documentation as our technical reference. If the documentation is incorrect or outdated, we are left completely unprotected from a technical standpoint.

The same applies to certification materials as well. I have already completed almost all certifications, and I have found some very serious documentation errors there too.

User Space Firewall (USFW) support on Security Gateways

https://support.checkpoint.com/results/sk/sk167052

Software Releases for LightSpeed QLS / MLS and Check Point Firewall 9000, 19000, 29000 Appliances

https://support.checkpoint.com/results/sk/sk179432

ATRG: SecureXL

https://support.checkpoint.com/results/sk/sk153832

Re: UPPAK Becoming Mandatory on R82.10? Important Findings About KPPAK Support, Boot Loops on 19000

Chris_Atkinson — Fri, 15 May 2026 15:48:37 GMT

Note USFW and UPPAK are not the same thing neither is KSFW and KPPAK

Please be careful not to use them interchangbly as it creates confusion.

Re: UPPAK Becoming Mandatory on R82.10? Important Findings About KPPAK Support, Boot Loops on 19000

israelfds95 — Fri, 15 May 2026 17:45:05 GMT

Thank you for your feedback and for highlighting the importance of precise terminology.

I am aware of the technical differences between UPPAK/KPPAK and USFW/KSFW, and I agree that they should not be used interchangeably. In my post, I referenced sk167052 because it was the same SK that the Check Point engineer used to address the issue I encountered when switching from UPPAK to KPPAK on the 19100 appliance

Re: UPPAK Becoming Mandatory on R82.10? Important Findings About KPPAK Support, Boot Loops on 19000

WiliRGasparetto — Fri, 15 May 2026 20:41:33 GMT

Excellent analysis. This is a point many people overlook: installed capacity does not necessarily mean effectively usable capacity, depending on the architecture chosen. In the case of the 19100, choosing KSFW means not only underutilizing approximately 37% of the available CPU resources, but also introducing a documented operational risk. A great reflection on performance, capacity planning, and system stability.

Re: UPPAK Becoming Mandatory on R82.10? Important Findings About KPPAK Support, Boot Loops on 19000

Chris_Atkinson — Sat, 16 May 2026 11:59:08 GMT

In that case there is detail missing somewhere as changing SXL modes doesn't alter the other (CoreXL) to my knowledge. How did you make the change?

See also the table at the bottom of sk167052.