> Source: [sk176711](https://support.checkpoint.com/results/sk/sk176711)

# sk176711 - NAT-T outbound packets sourced with incorrect IP interface.

| Property | Value |
|----------|-------|
| Solution ID | sk176711 |
| Date Created | 2021-12-02 |
| Last Modified | 2022-01-02 |
| Technical Level | General |

## Symptoms

- * Outbound NAT-T outgoing packets are sent from the incorrect link interface.
* Tunnel will form on correct link, however NAT-T traffic be send using a different IP interface
* Inbound traffic will use the correct IP addresses, however the reply Outbound will use the incorrect IP address as the source.

## Cause

NAT-T packets are sent through a different interface than the interface that received the traffic (acceleration is enabled).

## Solution

This problem was fixed. The fix is included starting from:

* [Jumbo Hotfix Accumulator for R80.40](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk165456&partition=Basic&product=All) starting from Take 126
* [Jumbo Hotfix Accumulator for R80.30](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk153152) starting from Take 241

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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