Some IPv6 connections randomly stop passing through ClusterXL in High Availability mode

Product: ClusterXL
Version: R80.40 (EOS), R81 (EOS), R81.10 (EOS), R81.20
Platform: All
Last Modified: 2023-11-23

Symptoms

• Some IPv6 connections randomly stop passing through ClusterXL in High Availability mode.
• Traffic capture on the Active cluster member shows that during the IPv6 TCP handshake, after the Active cluster member receives the [SYN-ACK] packet, the Active cluster member responds with an [ACK] packet that contains the wrong ACK sequence.

For example, Wireshark shows this wrong [ACK] packet in the "Info" column as "[TCP ACKed unseen segment]"

Solution

This problem was fixed. The fix is included in:

• Jumbo Hotfix Accumulator for R81.20 starting from Take 26
• Jumbo Hotfix Accumulator for R81.10 starting from Take 110
• Jumbo Hotfix Accumulator for R81 starting from Take 89
• Jumbo Hotfix Accumulator for R80.40 starting from Take 198

If you choose not to upgrade, Check Point can supply a Hotfix. Contact Check Point 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 from the Security Management Server and Security Gateways involved in the case.

Hotfix installation instructions:
Refer to sk168597 - How to install a Hotfix.

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: 2023-05-10
Last Modified: 2023-11-23