# Cannot reach websites because of "Streaming Engine: TCP Invalid Retransmission" drops

**Product**: IPS  
**Version**: R81.10 (EOS), R81.20, R82  
**Last Modified**: 2025-12-21

## Symptoms  
- Decrypted traffic traversing the Security Gateway gets dropped for:  
  
  `Invalid segment retransmission. Packet dropped. Please refer to sk172266.  
  Streaming Engine: TCP Invalid Retransmission`

Traffic flow:

Client > Decryption Device > Check Point Gateway > Re-encryption Device > Server

- Disabling Brotli Accept-Encoding on the client or on the decryption device resolves the issue.

## Cause  
A TCP retransmission was sent because the server did not respond to the original request. In the original packet on the Check Point Security Gateway, Brotli Accept-Encoding was removed because it is not supported (see [sk179967](https://support.checkpoint.com/results/sk/sk179967)). When a TCP retransmission was sent, the packet contained Brotli Accept-Encoding, but the original packet no longer had it on the Check Point Security Gateway. This is the reason for the "TCP Invalid Retransmission" drops.

## 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 44  
- [Jumbo Hotfix Accumulator for R81.20](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.20/Default.htm) starting from Take 99  
- [Jumbo Hotfix Accumulator for R81.10](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.10/Default.htm) starting from Take 183

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**: 2023-07-20  
**Last Modified**: 2025-12-21