> Source: [sk31382](https://support.checkpoint.com/results/sk/sk31382)

# sk31382 - "TCP packet out of state" drop message in log

| Property | Value |
|----------|-------|
| Solution ID | sk31382 |
| Date Created | 2005-12-16 |
| Last Modified | 2026-05-18 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20, R81.10 (EOS), R81 (EOS) |

## Symptoms

- * "*TCP packet out of state*" drop message in log.

* The "`fw ctl zdebug drop`" command shows that traffic is being dropped for "*TCP packet out of state: First packet isn't SYN*"/

* Wireshark captures show that the full TCP 3-way handshake is not completing.

## Cause

One or more of the causes below results in this issue:

* Connection halt during ClusterXL failover - services that are not synchronized on the cluster.  

* Security Policy install occasionally causes ClusterXL failover, and if connections are not set to keep data or rematch, they are interrupted.  

* Aggressive aging on a highly loaded Gateway / cluster  

* The traffic is non-TCP RFC compliant.  

* SmartLog shows that traffic is being dropped as "*TCP packet out of state: First packet isn't SYN* "  

* Session is expired at time of the SYN/ACK or ACK packet's arrival.

## Solution

This solution requires authentication. Please log in to view the full solution.

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