> Source: [sk180530](https://support.checkpoint.com/results/sk/sk180530)

# sk180530 - NAT-T traffic from VPN clients does not match implied rule

| Property | Value |
|----------|-------|
| Solution ID | sk180530 |
| Date Created | 2023-01-29 |
| Last Modified | 2023-07-19 |
| Technical Level | General |
| Products | Endpoint Security |
| Versions | Cloud, E89.X, E88.X |

## Symptoms

- * NAT-T traffic may stop matching the implied rule after policy installation and is dropped with "`IKE_NAT_TRAVERSAL Traffic Dropped from x.x.x.x to y.y.y.y`" message in SmartLog.
* VPN clients cannot connect to the gateway and fail with "`Negotiation with site failed`" message.
* The "`fw tab -t natt_port -u -f`" command does not show entry for NAT-T port. In working situation, it should show an entry with 1194 (HEX for port 4500)
* IKED debug shows IKED gets killed with signal 6 (SIGABRT). Durign the cleanup and exit it clears the natt_port table and restarts automatically
* Issue can happen after creating LDAP group object from Smart Console and pushing policy with the change

## Cause

Entry for NAT-T port (4500) ? removed from the *natt_port* table?.

## 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 8
* [Jumbo Hotfix Accumulator for R81.10](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.10/Default.htm) starting from Take 95
* [Jumbo Hotfix Accumulator for R81](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81/Default.htm) starting from Take 82
* [Jumbo Hotfix Accumulator for R80.40](https://sc1.checkpoint.com/documents/Jumbo_HFA/R80.40/Default.htm) starting from Take 198

If you choose not to upgrade, [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, collect these files:

1. [CPinfo](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92739) file from the Management Server involved in the case.
2. [CPinfo](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92739) file from the Security Gateway / each Cluster Member 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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