> Source: [sk182267](https://support.checkpoint.com/results/sk/sk182267)

# sk182267 - Tunnel Testing fails after an upgrade

| Property | Value |
|----------|-------|
| Solution ID | sk182267 |
| Date Created | 2024-04-30 |
| Last Modified | 2024-10-22 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R81.20, R81.10 (EOS), R81 (EOS) |
| OS | Gaia |

## Symptoms

- * Tunnel Testing traffic fails on R81.20 ClusterXL HA gateways.
* Packet captures show that the peer responds with "`ICMP Port Unreachable`" messages after Cluster gateway responds to Tunnel Testing packet initiated from the peer Security Gateway.

## Cause

The Security Gateway treats a tunnel testing reply source 18234 as a new connection, and performs Hide NAT.

## Solution

This problem was fixed. The fix is included in:

* [Jumbo Hotfix Accumulator for R81.20](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.20/Default.htm) starting from Take 79
* [Jumbo Hotfix Accumulator for R81.10](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.10/Default.htm) starting from Take 158
* [Jumbo Hotfix Accumulator for R81](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81/Default.htm) starting from Take 106

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).

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