# Security Gateway drops packets with fwconn_chain_rematch_cache FAILED when ISP Redundancy enabled

**Product**: Security Gateways  
**Version**: R81.10 (EOS), R81.20, R82  
**Last Modified**: 2025-01-27

## Symptoms

- After upgrade, users have an unstable connection to resources behind a Security Gateway when ISP Redundancy and QoS blades are enabled.
- The Security Gateway drops packets. Output of "`fw ctl zdebug + drop`" shows:

```
[fw4_19]:fw_log_drop_ex: Packet proto-17 1.2.3.4:12660- > 5.6.7.8:53 dropped by fwchain_continue_do Reason: fwconn_chain_rematch_cache FAILED, while trying to update the connection cache on the chain:
```

- Traffic captures show that the dropped packets arrive to the second ISP link configured in the ISP Redundancy blade.

## 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 10
- [Jumbo Hotfix Accumulator for R81.20](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.20/Default.htm) starting from Take 90
- [Jumbo Hotfix Accumulator for R81.10](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.10/Default.htm) starting from Take 171

If you choose not to upgrade, Check Point can supply a **Hotfix**. [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 the Hotfix.

For faster resolution and verification, please collect [CPinfo files](http://supportcontent.checkpoint.com/solutions?id=sk92739) from the Security Management Server and Security Gateways involved in the case.

**Hotfix installation instructions:**

Refer to [sk168597 - How to install a Hotfix](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk168597).

#### 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**: 2024-11-04  
**Last Modified**: 2025-01-27