> Source: [sk60331](https://support.checkpoint.com/results/sk/sk60331)

# sk60331 - VPN connection fails on a previously-established tunnel, IKE phase 1 packet sent before VPN connection fails

| Property | Value |
|----------|-------|
| Solution ID | sk60331 |
| Date Created | 2010-12-29 |
| Last Modified | 2023-05-07 |
| Technical Level | Advanced |

## Symptoms

- * A VPN connection fails for a tunnel that was established previously.

* IKE debug shows that IKE Main Mode Phase 1 packet is sent before the VPN connection fails.

* VPN debug on the Security Gateway shows this error message:

  `fwisakmp_new_sa_notify: Got an error from isakmpd type 3`
* Kernel debug for traffic drops on the Security Gateway shows these drops for IKE traffic:

  `Packet dropped: Clear text packet should be encrypted`
* Port 500 traffic to the peer is dropped:

  `Packet dropped: vpn_encrypt_chain Reason: no encryption key for destination;`
  ;

## Cause

The Check Point Control Connections setting is disabled in the Global Properties in SmartConsole / SmartDashboard.

As a result, the Security Gateway inspects Phase 1 packets as encrypted. Because Phase 1 packets are always clear text packets, the Security Gateway drops them.

**Note** - These errors and drops can indicate other issues, if it is not about an ISAKMP packet.

## Solution

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

---

# Agent Instructions

This content is from the Check Point Support Center (https://support.checkpoint.com), the official knowledge base for Check Point cybersecurity products.

## Navigating This Knowledge Base

- **Complete index**: [llms.txt](https://support.checkpoint.com/llms.txt)
- **All SK articles**: [SecureKnowledge Sitemap](https://support.checkpoint.com/sitemaps/secureknowledge-sitemap-index.xml)
- **SK article URL pattern**: `https://support.checkpoint.com/results/sk/{skId}`
- **Markdown responses**: AI bot User-Agents automatically receive `text/markdown` content