# Security Gateway drops HTTP/2 traffic and generates a core dump file for the FWK daemon

**Product:** HTTPS Inspection, Scalable Chassis, Security Gateways, VSX (Traditional)

**Version:** R81.10 (EOS), R81.20, R82  
**OS:** Gaia  
**Last Modified:** 2025-06-23

## Symptoms

- When HTTPS Inspection is enabled, the Security Gateway drops HTTP/2 traffic and generates a core dump file for the FWK daemon.
- The `/var/log/dump/usermode/` directory on the Security Gateway contains a core dump file for the FWK daemon.
- The affected versions are:
  - R81.10: starting from Jumbo Hotfix Takes 170 - T174
  - R81.20: starting from Jumbo Hotfix Takes 89 - T99
  - R82: starting from Jumbo Hotfix Takes 10 - 14

## Cause

A rare issue in HTTP/2 multiplexing may lead to traffic disruption.

## Solution

This problem was fixed. The fix is included in:

- [Jumbo Hotfix Accumulator for R82](https://sc1.checkpoint.com/documents/Jumbo_HFA/R82/Default.htm) starting from Take 25
- [Jumbo Hotfix Accumulator for R81.20](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.20/Default.htm) starting from Take 101
- [Jumbo Hotfix Accumulator for R81.10](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.10/Default.htm) starting from Take 177

If you choose not to upgrade, [Contact Check Point Support](https://www.checkpoint.com/support-services/contact-support/) to get a Hotfix for this issue.

A Support Engineer will make sure the Hotfix is compatible with your environment before providing it.

For faster resolution and verification, collect these files:

1. [CPinfo](https://support.checkpoint.com/results/sk/sk92739) file from the Management Server involved in the case.
2. [CPinfo](https://support.checkpoint.com/results/sk/sk92739) file from the Security Gateway / each Cluster Member involved in the case.

**Hotfix installation instructions:**

Refer to [sk168597 - How to install a Hotfix](https://support.checkpoint.com/results/sk/sk168597).

---

This **workaround** is also available:

You can disable HTTP/2 support on the Security Gateway, which will cause all web traffic to fall back to HTTP/1.

**To disable HTTP/2:**

1. `#ckp_regedit -a SOFTWARE\\CheckPoint\\FW1 IGNORE_ALPN_EXTENSION 1`
2. `#fw fetch local`
3. `#cpstop`
4. `#cpstart`

**To re-enable HTTP/2:**

1. `#ckp_regedit -a SOFTWARE\\CheckPoint\\FW1 IGNORE_ALPN_EXTENSION 0`
2. `#fw fetch local`
3. `#cpstop`
4. `#cpstart`

#### NOTE

This solution has been verified for the specific scenario, described by the combination of Product, Version and Symptoms. It may not work in other scenarios.

## Article Properties

**Access Level:** General  
**Status:** Approved by TAC  
**Date Created:** 2025-05-08  
**Last Modified:** 2025-06-23